TURFGRASS WEED CONTROL
Gwen Stahnke  
Revised December 17, 2008
Influence of Cultural Practices on Weed Encroachment
A major reason for weedy lawns is poor turf culture. Any effort to control weeds in turf should start with improving cultural practices. A goal of cultural weed control is to maximize turf density and maintain healthy, disease-free turf for a major part of every year. Some of the most important cultural practices are discussed below.
Mowing  Mowing practices have more impact on weed invasion in turf than any other cultural practice. Infrequent mowing, where turf is severely scalped, causes root dieback and forces regrowth from axillary buds, which consumes stored carbohydrates and results in thin turf that is slow to recover and is less dense. In hot weather, turf may die in irregular patches after severe scalping. Reduced turf density allows weed invasion due to lack of competition. Once weeds invade, they often spread rapidly, since many (rosette types) are relatively unaffected by the infrequent scalpings.
Regular mowing (i.e., about weekly) allows turf to achieve maximum density throughout the year. Under these conditions, turf will compete favorably with many common weed species, including common dandelion, Taraxacum officinale.
Proper mowing height is critical to maintaining turf density. In general, mowing below optimum height increases invasion of weedy grasses such as annual bluegrass (Poa annua) . Some desirable grasses, such as Kentucky bluegrass (Poa pratensis) and red fescue (Festuca rubra) may not do well if continually mowed low. Acceptable mowing heights for commonly used turfgrasses are below.
Mowing Height Ranges for Northwest Turfgrasses

Grass	Optimum Height Range (inches)	
Colonial bentgrass	0.5 to 1	
Chewings fescue	1 to 2.5	
Red fescue	2.5	
Hard fescue	1 to 2.5	
Tall fescue	1.5 to 3*	
Perennial ryegrass	1 to 2.5	
Kentucky bluegrass	1.5 to 2.5	
*Assumes improved varieties.
Irrigation  This ranks with mowing in impact on weed encroachment. Excess irrigation is a primary reason annual bluegrass invades many lawns. Surface wetness aids seed germination and also shifts the competitive edge toward existing annual bluegrass plants. Proper irrigation means thoroughly wetting the root zone, then allowing soil to dry until desirable grasses begin to wilt. Thus, turf density remains high, and surface conditions do not aid weed seed germination.
Lack of irrigation (e.g., prolonged summer drought) causes turf to go dormant and survive via crowns, rhizomes, and stolons. Turf density decreases, which allows weeds to compete freely once fall rains come or irrigation begins. Once weeds are established, they often thrive under this drought cycle because many are exceptionally deep rooted. Lawns allowed to go dormant every summer require more intensive efforts to control weeds chemically than lawns that are irrigated enough to ensure optimum turf density.
Fertilization  The primary goal of any long-term fertilization program should be to use the least amount of fertilizer necessary to maintain quality turf. Many home lawns can perform reasonably well with 2 to 4 lb of available nitrogen (N) per 1,000 sq ft of lawn annually, depending on soil type, the area’s use, and grass species. Special-use areas require more inputs. Excess N may stimulate invasion of annual bluegrass or undesirable bentgrass species. It also may stimulate diseases such as Fusarium patch or Drechslera leaf spot, which may severely thin turf. Inadequate N levels may result in gradual loss of turf density and more rust and red thread diseases.
Proper nutrient balance ensures long-term turf vigor. N-P-K balance should be about 4-1-3 or 6-1-4 annually. Too much phosphorus (P) may encourage annual bluegrass; too little may result in increased diseases such as Fusarium patch and red thread. On soils that are not pure sand, a safe rule of thumb is to apply 1 lb P per 1,000 sq ft per year if a soil test indicates it is needed. East of the Cascades, P usually is adequate. Do not apply P in late fall or winter near water sources, to limit the risk of leaching. Use a soil test to find the correct amount of nutrient to apply rather than guessing what to apply.
Long-term research on putting turf demonstrates the importance of adequate levels of sulfur (S) to minimize encroachment of annual bluegrass. Normally, 2 to 3 lb of elemental S per 1,000 sq ft of turf per year is adequate when used over time. The importance of sulfur nutrition on home lawns is still being researched.
Removal of clippings during mowing significantly increases fertilizer requirements. Tests indicate from 25 to 50% of applied N may be removed with clippings. Removing clippings may deplete nutrients in soil and ultimately lead to loss of turf density and increased weed invasion. It is good to return clippings to the site when possible.
Thatch control  Thatch is accumulated living and dead stems and roots between the soil surface and green vegetation. The accumulation is common and is a leading cause of turf failure. Because roots must penetrate thatch to reach the soil, excess thatch often results in poor drought tolerance and, once weather is dry, may lead to localized dry spots and dead turf. Excess thatch also decreases efficacy of fertilizer applications. Finally, thatchy lawns are often spongy and tend to scalp badly during mowing.
While excess thatch may lead directly to weed invasion, worse weed problems may result from attempts to remove thatch. Mechanical dethatchers can strip away not only thatch but desirable turf as well. Countless examples exist where weeds severely invaded lawns that were destroyed by incorrect efforts to remove thatch.
The key to proper dethatching is to remove thatch before it exceeds 0.75 to 1 inch. There is little danger of severely injuring turf in this case since most roots penetrate the thatch and are anchored in the soil. On lawns with heavy thatch (in excess of 1 inch), removal must be gradual over a period of perhaps 2 or 3 yr. At any given dethatching, avoid removing more than 0.5 inch of thatch. Also, if you dethatch the area more than once, do so at approximately 45-degree angles to avoid tearing out large chunks of turf. For quickest recovery, remove thatch before a major growth period. In western Oregon and Washington, April may be slightly better and early fall (late August/early September) slightly less desirable. Spring or fall is equally appropriate east of the Cascades.
Caution  Information in this handbook is not intended to be a complete guide to herbicide use. Before using any chemical, read the container label recommendations. Before a chemical can be recommended for a specific use, it must be thoroughly tested. Following the recommendation on the manufacturer’s label can prevent many problems from arising through the wrong use of a chemical.
Chemical Control of Broadleaf Weeds in Turf
Relatively few herbicides currently are used to control broadleaf weeds in turf. Years of observation allow us to accurately predict the activity of these chemicals. This section briefly summarizes several herbicides and herbicide mixtures. Weed susceptibilities to these materials are in the table at the end of this chapter.
TURFGRASS—Broadleaf Weeds
•  2,4-D (many names)
Rate  See label
Time  Apply when broadleaf weeds listed on label are actively growing.
Remarks  2,4-D is a foliar- or root-absorbed translocated herbicide available as amine salts and low-volatile esters. Amines are generally safe in a wide range of temperatures. Esters are useful in cool, rainy weather but are more likely to volatilize. 2,4-D is effective on dandelion, false dandelion, and plantains but weak on clover and other hard-to-kill weeds. 2,4-D is best used in mixtures for broad-spectrum weed control.
Caution  2,4-D may injure sensitive grasses such as bentgrass (turf) and roughstalk bluegrass when applied at high rates or during periods of environmental stress. Make sure to follow the regulations in eastern Washington for formulation and application timing allowed.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
•  bromoxynil (Broclean Wolfpack Advanced Herbicide, for sod farms)
Rate  See label
Time  Must be applied to actively growing weed seedlings (less than four-leaf stage, 2 inches tall, or 1 inch in diameter) for optimal control.
Remarks  Broclean is available as an octanoic acid ester formulation of bromoxynil. A selective postemergence herbicide, it controls certain broadleaf weeds in seedling and established nonresidential turfgrass, noncropland, and industrial sites. Acts on contact with very little persistence. Established turfgrasses tolerant to bromoxynil are bentgrasses, Kentucky bluegrass, fescues, ryegrass, bermudagrass, zoysiagrass, and St. Augustinegrass. It is active on a range of weeds, including annual sowthistle, field pennycress, lambsquarters, nightshades (black, eastern black, cutleaf, hairy, and silverleaf), green and Pennsylvania smartweed, pepperweed, and shepherdspurse. It will suppress Canada thistle only by burning down the top growth. See label for tank-mix recommendations with specific herbicides and for cautions and additional weeds that those mixtures control.
Caution  Leaves may burn if plants are stressed at time of application. Apply to dry foliage when weather is not extreme, to minimize temporary leaf burn. Do not apply with fertilizers if leaf burn is a concern due to environmental conditions. Screens should not be finer than 50 mesh in nozzle tips and in-line strainers on the sprayer.
Site of action  Group 6: photosynthesis II inhibitor
Chemical family  Nitrile
•  carfentrazone-ethyl  (QuickSilver T&O Herbicide)
Rate  See label
Time  Apply when broadleaf weeds listed on label are actively growing. Do not apply when conditions favor spray drift or poor spray coverage. Do not exceed 6.7 fl oz/A (0.1 lb ai/A) per application or 0.4 lb ai/A per season. Allow at least 2 wk between sequential broadcast applications. Do not apply by air or through any type of irrigation system.
Remarks  QuickSilver T&O Herbicide is a contact herbicide with little or no residual activity that provides selective postemergence control of broadleaf weeds and silvery thread moss (Bryum argenteum)  in turfgrass. It is an aryl triazolinone herbicide that interrupts chlorophyll synthesis and produces metabolic byproducts that disrupt plant cell membranes. This process occurs only in susceptible green plants in the presence of light. Symptoms may appear on foliage in 24 hr or less in susceptible plants. Complete desiccation and death occur within 7 to 14 days of application. QuickSilver is rainfast within 1 hr after application. Established cool-season grasses generally tolerate applications at labeled rates. Tall fescue may yellow slightly within 3 to 5 days after application under some conditions. Recovery typically is within 4 to 7 days. If such injury cannot be tolerated, apply to a small test area before treating a large area. QuickSilver can be applied to the following species of turfgrass 7 days or more after emergence: creeping bentgrass, tall fescue, perennial ryegrass, and Kentucky bluegrass. 
Caution  Do not apply to carpetgrass, dichondra, or to lawns or turf with desirable clovers. Avoid spray drift to nontarget, desirable, susceptible plants such as vegetables, flowers, ornamentals, trees, and shrubs. Product can be tank-mixed with other products, but observe all label restrictions regarding turf tolerance of companion products when tank-mixed with QuickSilver T&O. Maintain spray solution at pH 5 to 8.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Triazinone
•  clopyralid (Lontrel T&O)
Rate  See label
Time  Apply to broadleaf weeds listed on label only on healthy, well-established turf that has a well-anchored root system.
Remarks  A foliar- and root-absorbed, highly translocated herbicide formulated as an amine salt. It is active on legumes, black medic, clover (red, hop, white, and sweet), thistles, knapweeds, and speedwell. Use on nonresidential turf such as athletic and recreational sports fields, cemeteries, golf courses, industrial sites, military bases, noncropland, parks, rights-of-way, schools, and other nonresidential turf roadsides.
Caution  A state restricted-use pesticide in Washington. For use on golf courses only in Washington. Oregon use is limited to golf courses, nurseries, and grass grown for seed or sod. Lontrel T&O is safe on bentgrass; Kentucky bluegrass; Chewings, creeping, and sheep fescue; tall fescue; and perennial ryegrass. May discolor or stunt turf that is not well established or that is stressed by unfavorable conditions. Do not contaminate irrigation ditches or water for irrigation or domestic uses. Susceptible trees or shrubs (legumes) will be injured if sprays contact exposed suckers and/or roots. Do not reseed turfgrass for 3 wk after application. Do not use on golf course putting greens or tees or on residential turf. Do not send clippings to a compost facility. Do not collect grass clippings for mulch or compost. Applicators must tell landowners/property managers not to use grass clippings for composting.
Site of action  Group 3: microtubule assembly inhibitor 
Chemical family  Pyridine
•  clopyralid + triclopyr (Confront)
Rate  See label
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  A foliar- and root-absorbed highly translocated herbicide formulated as an amine salt. It is active on legumes, docks, knotweed, and dandelions, among others. Use on nonresidential turf; e.g., athletic and recreation fields, cemeteries, golf courses, industrial sites, military bases, noncropland, parks, rights-of-way, schools, other nonresidential turf roadsides, and on sod farms.
Caution  A state restricted-use pesticide in Oregon and Washington. For use on golf courses only in Washington and Oregon. Clopyralid + triclopyr mixtures appear safe on tall fescue, Kentucky bluegrass, and perennial ryegrass but may injure bent-grasses, roughstalk bluegrass, and annual bluegrass. Do not use on residential turf. Do not send clippings to a compost facility or use for mulch or compost. Applicators must tell landowners/property managers not to use grass clippings for composting.
Site of action  (both) Group 4: synthetic auxin
Chemical family  (both) pyridine
•  dicamba (Banvel, Cruise Control, Diablo, Vanquish, Rifle, or Sterling Blue)
Rate  See label
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  Dicamba is a foliar- and root-absorbed translocated herbicide available in dimethylamine and sodium salt formulations. It is active on a wide range of weeds, including clovers, chickweeds, and yarrow. It is weak on Oxalis species (woodsorrel), violets, plantains, and pineapple weed, among others. Dicamba is widely used in mixtures to broaden the spectrum of weed control.
Caution  Dicamba persists in soil longer than other common broadleaf herbicides and can move with the wetting front of soil water. Used repeatedly at high rates, it can injure nontarget trees and shrubs via root uptake. As formulated in mixtures, dicamba is generally safe when applied at label rates.
Site of action  Group 4: synthetic auxin
Chemical family  Benzoic acid
•  dichlorprop (2,4-DP or many other products)
Rate  See label
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  2,4-DP is a foliar- or root-absorbed translocated herbicide available in many mixtures with many other ingredients, in ester and potassium salt formulations. Weed control spectrum is limited when used alone. In mixtures, it generally is more active than MCPP, which it replaces.
Caution  Tolerance of grasses to 2,4-DP appears to be similar to tolerance of 2,4-D. Aerial applications are prohibited. Broadcast applications are limited to 0.75 lb ae/A total in no more than two applications per year at least 30 days apart. Spot treatments are limited to 2 lb ae/A total in no more than two applications per year at least 30 days apart. Mixers and loaders supporting handgun applications must wear respirators. Do not apply within 25 ft of water. Reentry interval is 48 hr.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
•  dithiopyr (Dimension, Dynamo 40WSP, Dithiopyr 40 WSB)
Rate  See label
Time  Apply preemergence when soil is about 50°F (approximately when forsythia blooms). Apply postemergence to crabgrass and annual bluegrass when they are very small (below the first tiller stage).
Remarks  Dithiopyr is available in EC, 40WSB, and 40WSP formulations, as granules, and on fertilizers. It gives preemergent control of crabgrasses, foxtails, barnyardgrass, and a number of broadleaf weeds, including purslane, Oxalis species, and spurge. It also gives preemergent control of annual bluegrass (Poa annua). It gives postemergence control of crabgrass up to the first tiller growth stage. Dithiopyr appears to be safe on mature creeping bentgrass, Kentucky bluegrass, perennial ryegrass, tall fescue, and some fine fescues.
Caution  Do not use on seedling turf; injury will be severe. Do not apply to turf under environmental stress.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Pyridine
•  fluroxypyr (Spotlight)
Rate  See label
Time  Apply to actively growing broadleaf weeds as listed on label.
Remarks  Fluroxypyr is a nonvolatile ester for postemergence control of annual and perennial broadleaf weeds and woody brush in established turf, including residential lawn, golf courses, sports fields, sod farms, around commercial buildings, and other commercial turf areas. Mow newly seeded turf two or three times before application. Control may be less if applied to wet foliage. Product is rainfast within 1 hr after application. Can be tank-mixed with other postemergent broadleaf herbicides for additional control of white clover, black medic, dandelion, plantain, Oxalis species, and others.
Caution  Do not use Spotlight on golf course putting greens or tees. Do not let spray contact exposed suckers or exposed roots of shallow-rooted trees and shrubs, or injury may occur. To minimize grass injury potential, do not reapply within 4 wk. Avoid spraying when humidity is low and/or temperatures are high to avoid evaporation and spray drift. Do not tank-mix with a product containing boron; do not mix in equipment previously used to apply a product containing boron unless the tank and spray equipment have been adequately cleaned. Undiluted Spotlight and 2,4-D amine  concentrates are not compatible and cannot be mixed together in the same supply tank when using injection equipment; however, combinations of Spotlight and 2,4-D ester are compatible for this purpose.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
•  isoxaben (Gallery 75DF)
Rate  See label
Time  Apply before weed seed germinates.
Remarks  A preemergent herbicide that controls susceptible broadleaf weeds as they germinate. It is root-absorbed and has limited herbicidal activity once weeds emerge. Available as a dry flowable material. Controls chickweeds, clovers, Oxalis species, pineappleweed, narrowleaf plantain, spurge, and many other weeds.
Site of action  Group 31: inhibits cell wall synthesis Site B
Chemical family  Benzamide
•  MCPA  (several names) 
Rate  See label
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  A foliar- or root-absorbed translocated herbicide available in amine and sodium salts and in ester formulations. Its activity and spectrum of weed control are very similar to 2,4-D.
Caution  MCPA may injure sensitive grasses such as bentgrass (turf) and roughstalk bluegrass if applied at high rates or during periods of environmental stress.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
•  mecoprop (MCPP or many other products) 
Rate  See label
Time  Apply to actively growing broadleaf weeds on label.
Remarks  A foliar-absorbed translocated herbicide available in amine and potassium salt (mixes) formulations. It is effective on chickweeds when used alone but is weak on other broadleaf weeds. It is best used in mixtures with 2,4-D and dicamba where it broadens the spectrum of weed control and reduces injury to sensitive grasses. MCPP is safer on bentgrass lawns and greens than any other phenoxy compounds. Limit broadcast applications to 0.75 lb ae/A total in no more than two applications per year at least 30 days apart. Limit spot treatments to 1.2 lb ae/A total in no more than two applications per year at least 30 days apart. Do not apply by air or within 25 ft of water. Reentry interval is 48 hr.
Site of action  Group 4: synthetic auxin
Chemical family  Phenoxy acetic acid
•  mesotrione  (Tenacity)
Rate  See label
Time  Tenacity is a systemic preemergence and postemergence herbicide for the selective contact and residual control of weeds in turfgrasses. Applied preemegence, weeds absorb Tenacity during emergence from soil. Dry conditions after application may reduce the preemergence activity. If rain (0.15 inches) has not fallen within 10 days after a preemergence application, activate with 0.15 inches of irrigation. Used postemergence, susceptible weeds absorb Tenacity through foliar contact and soil absorption. Foliage of treated weeds cease growth after application, then turn white (loss of chlorophyll); death may take up to 3 wk. A repeat application is required after 2 to 3 wk for improved postemergence weed control. Add a nonionic surfactant in postemergence applications. Tenacity may temporarily whiten turfgrass foliage. In general, symptoms appear 5 to 7 days after application and last for several weeks. A repeat application to the same site causes less whitening of plant tissue. Tenacity is an effective herbicide for weed control prior to or during seeding of certain turfgrasses during turf renovation. Do not apply to newly germinated turfgrass until it has been mowed two times or approximately 4 wk after emergence. Young actively growing weeds are easiest to control. Efficacy will be reduced under moisture stress or when applied to mature weeds. Tenacity can be tank-mixed with other herbicides, but check label for tank-mixtures already tested. Herbicides not listed on the label as being tested for tank-mixtures must be tested for compatability, safety, and efficacy before treating large areas. In established turf, Tenacity is more effective as a postemergence application unless combined with another soil active herbicide. Tenacity should be combined with a preemergence herbicide for extended control of key annual monocot weeds such as crabgrass and foxtail. 
Remarks  For use on golf courses and sod farms. Do not use on golf greens. Maintain a 5-ft buffer between treated areas and putting greens. Do not exceed 5 fl oz/A per application to perennial ryegrass or fine fescues or mixed stands that contain greater than 50% perennial ryegrass and/or fine fescue. Withhold traffic on treated areas until spray has dried and irrigate lightly to move product from turf foliage before resuming normal irrigation to prevent movement onto sensitive species such as bentgrass. Do not plant any crop other than turfgrass species for 18 mo after the last application of Tenacity or injury may occur. Do not apply an organophosphate or carbamate insecticide within 7 days of a Tenacity application as turf injury may occur. Do not apply by air or through any type of irrigation system. Do not apply more than 16 oz/A per year (maximum of 0.5 lb/A of mesotrione per year). Restricted-entry interval is 12 hr.
Site of action  Group 27: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)
Chemical family  Triketone
•  metsulfuron-methyl  (Mansion Turf Herbicide, AmTide MSM 60DF Herbicide)
Rate  See label
Time  Apply to actively growing weeds listed on the label.
Remarks  For use on golf courses, lawns, noncrop nonagricultural areas, recreation areas, sod farms, and ornamental turf.
Do not apply to turf less than 1 yr old, or to turfgrass stressed by drought, insects, disease, cold, temperatures above 85°F on cool-season grasses, or poor fertility; injury may result. Adding nonionic surfactant of at least 80% ai at 0.25% v/v (1quart/100 gal) provides best performance but may temporarily increase turf chlorosis. Use spray volumes of 20 to 80 gal/A and pressures of 25 to 35 psi. Use large droplet size to minimize spray drift. Mansion can control annual sowthistle, Canada thistle, common chickweed, common groundsel, yarrow, curly dock, dandelion, henbit, lambsquarters, plantain, prostrate knotweed, prostrate spurge, wild carrot, wild garlic, and woodsorrel (Oxalis).
Caution  When overseeding, wait 3 mo after application. Do not apply to any body of water, including streams, irrigation water, or wells. Do not apply where water may run off onto agricultural land; crop injury may result.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
•  penoxsulam (Sapphire) 
Rate  See label
Time  Apply to actively growing weeds.
Remarks  For use on golf courses, lawns, general turf, school outdoor areas, and sod farms. Enhances control of white clover, dandelion, sedge weeds, ground ivy, chickweed, Oxalis, bittercress, pigweed, kyllinga, sagebrush, broadleaf plantain, and English lawn daisy. 
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylaminocarbonyltriazolinone 
•  quinclorac (Drive 75DF, Quinclorac 75DF, Drive XLR8)
Rate  See label
Time  Apply postemergence to actively growing weeds listed on label. Apply preemergence before weed seeds germinate.
Remarks  A selective herbicide with both preemergence and postemergence activity that gets tough broadleaf weeds and grasses such as clover; dandelion; English daisy; foxtail; common, slender, and thymeleaf speedwell; and crabgrass. Drive herbicide enters susceptible weeds through both foliage and roots. It is translocated throughout the plant and accumulates in the meristematic regions, where it disrupts plant growth. It has residual control of annual and perennial weeds through germinating seed uptake. Residual control is 60 to 90 days, depending on application rates, soil type, weed species, and moisture availability. After applying Drive, plants exhibit leaf and stem twisting and chlorosis. Grasses exhibit stunting, chlorosis, and a gradual reddening, followed by necrosis. Use methylated seed oil or crop oil concentrate additives for greater efficacy; see label for rates.
Caution  Do not mow 2 days before or after applying Drive 75DF, to maximize weed control. Mulch clippings on site the first three mowings after applying. Do not irrigate for 24 hr after applying; however, irrigation 2 to 7 days after application is recommended. Drive XLR8 is a liquid formulation that is rainfast in approximately 30 min. The liquid formulation can also be mixed with other postemergence broadleaf herbicides to increase the spectrum of control. Do not apply within 4 wk after perennial ryegrass or Kentucky bluegrass seedlings emerge. Applications before or after seeding a turf area will not significantly interfere with germination and growth of Kentucky bluegrass, annual bluegrass, buffalograss, tall fescue, or annual and perennial ryegrass. Must be applied before seedlings emerge. Fine fescues and creeping bentgrasses are only moderately tolerant. Do not apply to golf course collars or greens. Do not allow drift to desirable plants, especially those in the Solanaceae family such as tomatoes, eggplants, and bell peppers. Do not use clippings as mulch or compost around flowers, ornamentals, trees, or in vegetable gardens.
Site of action  Group 4: synthetic auxin
Chemical family  Quinoline carboxylic acid
•  sulfosulfuron (Certainty Turf Herbicide) 
Rate  See label
Time  Apply postemergence when target weeds are actively growing and not disturbed by mowing for at least 2 days after application.
Remarks  This is a postemergence, systemic herbicide with limited soil residual activity. It provides postemergence control of many annual and perennial sedges, grass and broadleaf weeds on highly managed turf, sod farms and native grass sites. It is a selective herbicide that can be used over the top of many perennial warm-season and selected cool-season turfgrasses. This product is recommended for use on creeping bentgrass, Kentucky bluegrass and Kentucky bluegrass mixtures with perennial ryegrass and/or fine fescue. Apply only when the grasses are actively growing and mowing is required. This product can control roughstalk bluegrass (Poa trivialis). It can be applied to residential and commercial turf sites, including apartment complexes, athletic fields, cemeteries, golf course fairways, tees and roughs, hotel properties, office complexes, parks, public turf areas, retail sites, storage facilities, school grounds, sod and turfgrass seed farms and other highly managed turfgrass areas. This product is absorbed by both the roots and foliage of the plants and rapidly inhibits the growth of susceptible weeds. Susceptible weed growth stops within 24 hr of treatment even though visual symptoms are slow to develop. Susceptible weeds usually show yellowing or browning within 2 to 3 wk. Warm, moist conditions following application will accelerate herbicidal activity. Cold, dry conditions will delay herbicidal activity. Weeds stressed by drought are less susceptible to this product. 
Caution  DO NOT apply directly to or within 4 ft of golf course putting greens. Using this chemical on permeable soils, particularly where the water table is shallow, may contaminate ground water. Heavy rain or irrigation within 2 hr after application may wash product off foliage, and a repeat application may be required for adequate control. Do not exceed a total of 2.66 oz/A product per year. Avoid contacting roots or foliage of susceptible nontarget vegetation, as injury may occur. This includes areas where this product may be washed or moved into contact with roots of desirable vegetation. Susceptible plants may be injured if seeded or transplanted into treated areas unless otherwise directed in the label. Applications fall, after temperatures have dropped and regular mowing is no longer required, may be more likely to injure turf and may delay spring green-up. Product may result in temporary chlorosis and discoloration and may affect the growth pattern of desirable turf. Symptoms generally appear 7 to 10 days after application and typically go within 21 to 28 days. Perennial ryegrass, fine fescues, and creeping bentgrass are more sensitive to this product.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  sulfonylurea
•  triclopyr (Turflon Ester Specialty Herbicide)
Rate  See label
Time  Apply to actively growing weeds listed on label.
Remarks  A foliar- and root-absorbed translocated herbicide available by itself in ester formulation and in mixtures with 2,4-D or clopyralid. Effective against violets, ground ivy, and Oxalis in Kentucky bluegrass, perennial ryegrass, and tall fescue. Triclopyr generally is less effective by itself than in mixtures. It can be tank-mixed with commonly used three-way herbicide mixtures to increase the weed control spectrum.
Caution  To minimize turf injury, do not treat if turf is under heat or drought stress. Repeat applications at least 4 wk apart. Mixtures with triclopyr in ester form have injured fine fescue turf after early spring applications in western Oregon. Do not apply to exposed roots of shallow-rooted trees and shrubs. Injury to Deodara cedar is associated with mixtures containing triclopyr in ester form when applied around budbreak. Triclopyr may injure bentgrass (turf) and roughstalk bluegrass. Keep out of lakes, streams, and ponds. Toxic to fish.
Site of action  Group 4: synthetic auxin
Chemical family  Pyridine
Herbicide Mixtures for Weeds in Turf
No single herbicide controls all weeds commonly found in turf. Mixing two or more herbicides can dramatically increase the spectrum of weed control. Most mixtures have a wide safety margin on desirable grasses. Some mixtures are specially formulated for sensitive grasses such as bentgrass (turf). Mixtures generally are available in amine salt and low-volatile ester formulations. Formulation seems to have no effect on long-term weed control in common uses. Ester formulations are the materials of choice in early spring, late fall, and during rainy weather. Amine salt formulations generally are safer than esters around nontarget plants.
TURFGRASS—Mixtures without Triclopyr
•  carfentrazone-ethyl + MCPA + MCPP + dicamba (Power Zone)
Rate  See label
Time  Apply to actively growing broadleaf weeds.
Remarks  Power Zone is an emulsifiable concentrate. Power Zone is a selective postemergence herbicide with superior cool-weather performance on established cool- and warm-season grasses for common and troublesome weeds in turfgrass such as spurge, pennywort, dandelion, and white clover. Evidence of injury can be seen within hours of application, and plants can die in 7 to 14 days. Safe on Kentucky bluegrass, annual bluegrass, annual ryegrass, perennial ryegrass, tall fescue, red or fineleaf fescue, and mixtures of cool-season species in noncropland (Kentucky bluegrass, tall fescue, smooth bromegrass, and orchardgrass). Uses include institutional, ornamental, and residential sites, sod production, and noncropland (rights-of-way, roadsides, medians, airports, and military installations). Spray solution must be above pH 5 and below pH 8.
Caution  Tolerance to Power Zone may vary; certain F1 hybrids of bermudagrass may yellow temporarily. Environmental conditions and certain spray tank additives (e.g., adjuvants, wetting agents, surfactants), liquid fertilizers, and tank-mixtures containing other emulsifiable concentrates may reduce selectivity on turfgrass. Do not apply to bentgrass greens, carpetgrass, dichondra, legumes, or lawns with desirable clovers. Do not apply to new grass seedlings until after the second mowing. Wait 3 to 4 wk to apply to newly sodded, sprigged, or plugged areas. Do not irrigate turfgrass within 24 hr after applying. Delay mowing 1 to 2 days before and after applying this product. Treated areas may be reseeded 2 wk after application. Do not apply when air exceeds 90°F. Do not apply to any body of water, wetlands, irrigation ditch banks, or shorelines.
Site of action  (carfentrazone-ethyl) Group 14: protoporphyrinogen oxidase inhibitor; (MCPA, MCPP, and dicamba) Group 4: synthetic auxin
Chemical family  (carfentrazone-ethyl) triazinone; (MCPA and MCPP) phenoxy acetic acid; (dicamba) benzoic acid
•  carfentrazone-ethyl + 2,4-D + MCPP + dicamba (Speed Zone) 
Rate  See label
Time  Apply to actively growing broadleaf weeds.
Remarks  Speed Zone is an emulsifiable concentrate. Speed Zone is a selective postemergence herbicide with superior cool-weather performance on established cool- and warm-season grasses for common and troublesome weeds in turfgrass such as spurge, pennywort, dandelion, and white clover. Evidence of injury can be seen within hours of application, and plants can die in 7 to 14 days. Safe to apply on Kentucky bluegrass, annual bluegrass, perennial ryegrass, tall fescue, red or fineleaf fescue, creeping and colonial bentgrass (excluding golf greens), and mixtures of cool-season species in noncropland (Kentucky bluegrass, tall fescue, smooth bromegrass, and orchardgrass). Uses include institutional, ornamental, and residential sites, sod production, and noncropland (rights-of-way, roadsides, medians, airports, and military installations). Spray solution must be above pH 5 and below pH 8.
Caution  Do not apply to bentgrass greens, carpetgrass, dichondra, legumes, and lawns with desirable clovers. Do not apply to new grass seedlings until after the second mowing. Delay applying for 3 to 4 wk on newly sodded, sprigged, or plugged areas. Do not irrigate turfgrass within 24 hr after application. Delay mowing 1 to 2 days before and after application. Treated areas may be reseeded 2 wk after application. Do not apply when air exceeds 90°F. Do not apply to any body of water, wetlands, irrigation ditch banks, or shorelines.
Site of action  (carfentrazone-ethyl) Group 14: protoporphyrinogen oxidase inhibitor; (2,4-D, MCPP, and dicamba) Group 4: synthetic auxin
Chemical family  (carfentrazone-ethyl) triazinone; (2,4-D and MCPP) phenoxy acetic acid; (dicamba) benzoic acid
•  2,4-D + fluroxypyr + dicamba (Escalade or Escalade Low Odor)
Rate  See label
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  Escalade is formulated to control weeds growing in Kentucky bluegrass, fescue, perennial ryegrass and bentgrass turf (excluding golf greens and tees). Used to control black medic, chickweed, clover, cocklebur, dandelion, knotweed, Oxalis species, plantain, thistle, and many other species of broadleaf weeds listed on the label. For turf, do not exceed two broadcast applications per year.
Caution  Do not apply to golf greens and tees, centipedegrass, St. Augustinegrass, dichondra, legumes, and lawns with desirable clovers. Avoid contact with exposed feeder roots of ornamental trees and shrubs. Avoid applying during excessively dry or hot periods unless irrigating. Do not apply to new grass seedlings until after second mowing. Wait 3 to 4 wk to apply to newly sodded, sprigged, or plugged areas. Do not irrigate turfgrass within 24 hr after application. Delay mowing 1 to 2 days before and after applying. Do not apply when air exceeds 90 F. Do not allow people (other than applicator) or pets on treatment area during application. Do not enter treatment area until spray has dried. Do not reseed for 3 to 4 wk after applying. Product can be mixed with some liquid fertilizers or liquid iron materials; however, test for compatibility before mixing in application equipment, due to product variability.
Site of action  (all) Group 4: synthetic auxin
Chemical family  (2,4-D) phenoxy acetic acid; (fluroxypyr) pyridine; (dicamba) benzoic acid
•  2,4-D + quinclorac + dicamba (Quincept)
Rate  See label
Time  Apply to actively growing grassy and broadleaf weeds listed on label.
Remarks  Provides broad-spectrum control of grassy and broadleaf weeds in residential and nonresidential turfgrasses. Sites include but are not limited to grounds or lawns around residential and commercial establishments, multifamily dwellings, military and other institutions, parks, airports, roadsides, schools, picnic grounds, athletic fields, houses of worship, cemeteries, golf courses, and sod farms. Controls newly germinated one- to two-leaf crabgrass, to one-tiller crabgrass when crabgrass has matured to five tillers or greater. Quinclorac contributes grassy weed control and is absorbed by foliage and roots and translocated throughout the plant. Susceptible grasses demonstrate stunting, chlorosis, and gradual reddening followed by necrosis and death. Yellowing that may occur on some grasses may be reduced by adding chelated iron or sprayable solution nitrogen. Apply to fine fescue only when it is part of a blend.
Caution  Do not apply to newly seeded grass until after the third mowing or 4 wk after emergence. Do not mow for 2 days before or after applying. Do not apply by air or through any type of irrigation system. Application to established creeping bentgrass must be in two to three split applications. Do not exceed 1.5 lb ai/A quinclorac per year. Do NOT use on golf course greens, tees, or collars. Do NOT use on lawns with desirable clovers or legumes.
Site of action  (all) Group 4: synthetic auxin;
Chemical family  (2,4-D) phenoxy acetic acid; (quinclorac) quinoline carboxylic acid; (dicamba) benzoic acid
•  2,4-D + 2,4-DP  (many products) or 
•  2,4-D + MCPP + dicamba or
•  2,4-D + MCPP-P + dicamba (Trupower 3)  or 
•  2,4-D + 2,4-DP + dicamba or
•  MCPA + MCPP + dicamba or
•  2,4-D + 2,4-DP + MCPP (Spoiler) 
Rate  See labels
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  These mixtures are available in amine salt and ester formulations. They generally are effective on a broad range of weeds and are safe on most grasses due to relatively low component rates. As a group, these will not control Oxalis species, violets, lawn ivy, or spurge. Retreatment generally is necessary on difficult weeds such as yarrow, lawn daisy, and clovers.
Site of action  (all) Group 4: synthetic auxin
Chemical family  (2,4-D, 2,4-DP, MCPP, and MCPA) phenoxy acetic acid; (dicamba) benzoic acid
•  MCPA + fluroxypyr + dicamba (Triple Shot) 
Rate  See label
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  This product is for selective broadleaf weed control in ornamental lawns, parks, cemeteries, athletic fields, golf courses (excluding any bentgrass tees) and sod farms.
Caution  Do not use on Dichondra, or on lawns with desirable clovers. Avoid fine mists. Use lawn-type sprayer with coarse spray so wind drift is less likely. Avoid contact with exposed feeder roots of ornamentals and trees. Best control is from spring or early fall applications, when weeds are actively growing. Use higher rate on label for hard-to-control weeds. Do not apply to newly seeded grasses until well established. Avoid broadcast applications when air exceeds 90°F. Spot treatments at temperatures over 90°F may injure turf. Do not mow turfgrass 1 to 2 days before or after application. Wait 3 or 4 wk after application to reseed.
Site of action  (all) Group 4: synthetic auxin; 
Chemical family  (MCPA) phenoxy acetic acid; (fluroxypyr) pyridine; (dicamba) benzoic acid

TURFGRASS—Mixtures with Triclopyr
•  2,4-D + triclopyr (Turflon D, Chaser, or Turflon II Amine) or
•  clopyralid + triclopyr (Confront) 
Rate  See label
Time  Apply to actively growing broadleaf weeds listed on label.
Remarks  The 2,4-D + triclopyr mixture is available in amine salt and ester formulations; the clopyralid + triclopyr mixture is available only as an amine salt. Both mixtures control a wide range of common weeds and are active on Oxalis species, lawn violets, lawn ivy, and spurge. Confront is weak on mouseear chickweed. Confront is for use on nonresidential turf such as athletic and recreational sports fields, cemeteries, golf courses, industrial sites, military bases, noncropland, parks, rights-of-way, schools, and other nonresidential turf roadsides.
Caution  A restricted-use pesticide in Washington and Oregon, for use on golf courses only. Mixtures with triclopyr ester may injure fine fescues and other sensitive grasses particularly in early spring. Damage to Deodara cedar has been associated with mixtures containing triclopyr ester applied in spring around bud break. Use Confront only on tall fescue, bluegrass (turf), or perennial ryegrass unless injury to other species can be tolerated. Do not use Confront on residential turf. Do not send clippings to a compost facility. Do not collect grass clippings for mulch or compost. Applicators must tell landowners and managers not to use grass clippings for composting.
Site of action  (all) Group 4: synthetic auxin
Chemical family  (2,4-D) phenoxy acetic acid; (triclopyr and clopyralid) pyridine
TURFGRASS—Lawn Moss
•  carfentrazone-ethyl (QuickSilver T&O Herbicide)
Rate  See supplemental label
Time  During daylight, apply to moss in turfgrasses listed on label.
Remarks  QuickSilver T&O Herbicide is a contact herbicide with little or no residual activity that provides selective postemergence control of broadleaf weeds and silvery thread moss (Bryum argenteum) in turfgrass. It is an aryl triazolinone herbicide, which interrupts chlorophyll synthesis and produces metabolic byproducts that disrupt plant cell membranes. This process occurs only in susceptible green plants in the presence of light. Symptoms may appear on foliage in 24 hr or less in susceptible plants. Complete desiccation and death occur 7 to 14 days after application. QuickSilver is rainfast within 1 hr after application. Established cool-season grasses generally tolerate applications at labeled rates. Tall fescue may yellow slightly within 3 to 5 days after application under some conditions. Recovery typically is within 4 to 7 days. If such injury cannot be tolerated, apply to a small test area before treating a large area.
QuickSilver produces herbicidal symptoms only in the weed parts it contacts directly. For best results, select a spray volume and nozzle system that ensure thorough, uniform coverage and minimize fine spray droplets. Spray droplets larger than 400 microns may reduce coverage and reduce weed control. Apply in spray volumes of 20 to 175 gal/A (0.5 to 4 gal/100 sq ft). Use higher spray volumes on dense weed populations, turfgrass canopies, or where uniform coverage is difficult to obtain.
QuickSilver can be applied at 7 days or more after emergence to creeping bentgrass, tall fescue, perennial ryegrass, and Kentucky bluegrass. 
Caution  Do not apply to carpetgrass or dichondra or to lawns or turf with desirable clovers. Avoid spray drift to nontarget, desirable, susceptible plants such as vegetables, flowers, ornamentals, trees, and shrubs. Do not apply when conditions favor spray drift or poor spray coverage. Do not exceed 6.7 fl oz/A (0.1 lb ai/A) per application or 0.4 lb ai/A per season. Allow at least 2 wk between sequential broadcast applications. Do not apply by air or through any type of irrigation system. Quicksilver can be tank-mixed with other products, but observe all label restrictions on turf tolerance of companion products. Maintain spray solution between pH 5 and pH 8.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Triazinone
•  ferrous sulfate
Rate  0.5 to 1.5 lb product per 1,000 sq ft; see label
Time  Apply to moss in early spring and fall when grass is actively growing and will fill in the bare areas after moss dies.
Remarks  Iron compounds act as contact herbicides and are available in granular and liquid formulations. Treatments are effective whenever moss is actively growing. For detailed information on moss control, refer to Oregon State University Extension publication FS 55, Controlling Moss in Lawns, online at http://extension.oregonstate.edu/catalog/html/fs/fs55/
Caution  Iron stains concrete and painted surfaces. Keep sprays away from these surfaces. Turf may be temporarily discolored (blackened) at high application rates.
•  potassium salts of fatty acids (Moss Max)
Rate  See label
Time  Apply to moss in early spring and fall when grass is actively growing and will fill in the bare areas after moss dies.
Remarks  Potassium salts of fatty acids act as contact herbicides and are available as liquid concentrates. Treatments are effective whenever moss is actively growing. For details on moss control, refer to Oregon State University Extension publication FS 55, Controlling Moss in Lawns, online at http://extension.oregonstate.edu/catalog/html/fs/fs55/
Caution  May temporarily discolor treated grasses. Product is safe on concrete and other surfaces.

Annual Bluegrass Weed Control in Turf
Selective control of annual bluegrass in turf is a big challenge in the Pacific Northwest. There are no tried-and-true procedures. All breakthroughs reported in other regions of the United States are less effective here than in climates with greater environmental stress. Current strategies involve selective preemergence herbicides, selective pre- and early postemergence herbicides, and selectively suppressing growth with turfgrass growth regulators.
Selective preemergence herbicides prevent annual bluegrass seed from germinating. In general, while most available preemergence herbicides are effective in killing germinating seedlings, they have not provided effective annual bluegrass control. Part of the problem is that there are both annual and perennial types of annual bluegrass in irrigated turf. In addition, it can produce seed any time of the year but seeds most heavily in spring, with a second, less heavy flush of seeds in fall. Finally, annual bluegrass seed can germinate nearly any time of year. These factors make it difficult to target applications. Repeated treatments of preemergence herbicides to maintain herbicide activity year-round may stunt root growth of desirable grasses and predispose them to diseases or reduced stress tolerance. Selective preemergence and early postemergence control is viable with ethofumesate applied to pure seedling stands of perennial ryegrass. Ethofumesate is active on young annual bluegrass up to about the four-leaf stage. In mature perennial ryegrass, Kentucky bluegrass, or tall fescue, annual bluegrass can be controlled with three applications of ethofumesate in fall. Start in mid-October and reapply at 3- to 4-wk intervals. Activity generally is not apparent after the first application, but yellowing begins between the second and third applications. In western Oregon, the death of the treated annual bluegrass may not be apparent until March, depending on the year. Kentucky bluegrass and tall fescue may be slightly injured or discolored. Some tests achieved 90 to 100% control after one series of treatments. Annual bluegrass may reinvade from seed once the herbicide dissipates.
Selectively suppressing annual bluegrass growth has been successful in many parts of the country. The object is to retard annual bluegrass more than desirable grasses so the balance of competition shifts in favor of the planted grasses. The strategy seems to work best in areas with cold winters and hot, humid summers. Annual strains of annual bluegrass are more sensitive than perennial strains. Reducing annual bluegrass to acceptable levels may take several years and require ongoing spring and fall treatments.
TURFGRASS—Annual Bluegrass
Selective preemergence
See preemergence herbicides listed for annual grasses.
Selective preemergence and early postemergence
•  ethofumesate (Prograss, Prograss EC Herbicide)
Rate  See label
Time  Apply to grasses listed as tolerant on label, when annual bluegrass is at less than the four-leaf stage. 
Remarks  Available only as an emulsifiable concentrate. It gives effective preemergent and early postemergent control of annual bluegrass in new seedings of perennial ryegrass.
Caution  Inhibits germination of most desirable cool-season grasses other than perennial ryegrass. Highly toxic to seedling fine fescues. Surface organic matter decreases the effectiveness of ethofumesate, so remove thatch and other debris before applying.
Site of action  Group 16: unknown
Chemical family  Benzofuran
Selective postemergence 
•  bispyribac-sodium (Velocity SG Herbicide) 
Rate  See label
Time  Apply when grass is actively growing, but before weeds form seedheads.
Remarks  Velocity may mildly discolor creeping bentgrass and perennial ryegrass. Discoloration begins 3 to 10 days after application. Vigorously growing grasses should outgrow symptoms within 3 to 14 days. If temporary turf chlorosis is a concern, avoid treating small patches of turf that are surrounded by untreated areas of turf. Velocity performs best under sunny conditions when daytime temperatures are between 65° and 80°F during and after application.
Caution  Do not apply Velocity to turfgrass with symptoms of heat stress or if significant heat stress is expected. Velocity may increase the susceptibility of creeping bentgrass to Pythium blight when conditions are favorable for infection. Do not apply to creeping bentgrass or perennial ryegrass mowed to less than 0.375 inch. Do not apply to golf greens and roughs. Velocity may not be effective against all biotypes of annual bluegrass.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Pyrimidinylthiobenzoate
•  ethofumesate (Prograss, Prograss EC Herbicide) 
Rate  See label
Time Apply to grasses listed as tolerant on label, before annual bluegrass reaches the four-leaf stage. 
Remarks  Effective only in a series of three or more treatments; single treatments are not effective. Some perennial strains of annual bluegrass may not be affected.
Caution  Kills fine fescues and roughstalk bluegrass and causes unsightly injury to most bentgrasses. Assess components of the turf carefully before beginning treatment.
Site of action  Group 16: unknown
Chemical family  Benzofuran
Selective growth suppression
•  paclobutrazol (Turf Enhancer 25C, 31-3-7 Fertilizer with TGR Poa annua Control; 14-0-29 High K Fertilizer with TGR Poa annua Control; or Cutdown PGR)
Rate  See label
Remarks  Available in liquid (25C) and granular formulations (mixed with fertilizer). Selectively suppresses annual bluegrass growth, allowing tolerant grasses to dominate turf. Long-term success requires annual retreatment. Tends to be more effective in turf with mainly annual Poa annua biotypes. Paclobutrazol is labeled for use on bentgrass, Kentucky bluegrass, and perennial ryegrass.
Caution  Not recommended for turf with more than 70% annual bluegrass. Do not use during periods of extreme environmental stress (e.g., heat, cold, drought). At high rates, Kentucky bluegrass and bentgrass turf may be discolored temporarily.
Site of action   Gibberellin biosynthesis inhibitor
Chemical family  Class B plant growth regulator  
Selective seedhead suppression
•  ethephon (Proxy) 
Rate  5 fl oz in 1 to 2 gal water/1,000 sq ft. See label for specific application intervals.
Time  Apply to golf, parks, and sports turf. Not for residential use.
Remarks  Proxy is used to suppress seedhead formation in Poa annua and white clover, among others, and also to suppress growth of certain cool- season grasses. It is foliarly absorbed and is most effective on actively growing healthy turf. Apply in a sufficient volume of water to provide uniform coverage. Proxy is rainfast in 2 hours. A spreader/sticker is not necessary. Do not reenter treated area until dry. Delay mowing until the day after the application.
Caution  Do not treat turfgrasses with poor root systems or growing under stress due to poor soil conditions. Do not use if thatch is excessive. Do not apply Proxy through any type of irrigation system. Mix only the amount of product you expect to use each day. Do not allow mixed solution to stand overnight. Scalping may occur on creeping bentgrass cultivars after more than two applications of Proxy for Poa seedhead suppression.
Site of action  Enhances release of ethylene gas
Chemical family  Phosphinic acid
Turfgrass growth suppression
•  trinexepac-ethyl (Primo MAXX, Podium, T-Nex 1AQ) 
Rate  See label for rates on specific grass types and mowing heights.
Time  Apply to actively growing grass, including home lawns, parks, recreation areas, golf course roughs, cemeteries, business sites, sports fields, and sod farms that are not under stress.
Remarks  Primo MAXX reduces mowing frequency and the amount of grass clippings. It also increases turfgrass density, color, and quality. Useful in difficult-to-mow areas; can minimize the need to edge along sidewalks, curbs, parking lots, driveways, flower beds, and fences and around posts, storage sheds, and trees. Primo MAXX reaches the growing point by foliar uptake and is rainfast after 1 hr. Water not needed to activate.
Caution  Any cultural practice that affects turf growth and vigor will influence turf response to Primo MAXX. Rates in the table on the label provide about 50% growth inhibition over a 4-wk period with little or no discoloration. With less-than-optimal growth conditions, rates may have to be reduced by 50% due to stress. Multiple applications of Primo MAXX can be made each growing season, but do not exceed a total of 7 fl oz/1,000 sq ft per year. If turf is going into dormancy due to high or low temperatures or lack of moisture, reduce Primo rate. To minimize turf injury, apply Primo MAXX , then wait at least 4 hr before mowing; or mow first, wait at least 1 hr, then apply Primo MAXX.
Site of action  Late gibberellin (GA1) biosynthesis inhibitor
Chemical family  Class A plant growth regulator
TURFGRASS—Nutsedge and Perennial Grass
•  bentazon (Basagran T/O)
Rate  See label
Time  Apply to actively growing weeds.
Remarks  Available as a soluble liquid. Bentazon acts as a contact herbicide to control yellow nutsedge, annual sedges, and broadleaf weeds, including chickweed and common purslane. It does not control purple nutsedge. Safe for use on established Kentucky bluegrass, fescues, bentgrass, perennial ryegrass, and several warm-season grasses. 
Caution  Do not apply to turf under stress from drought, cold, or other herbicides. Do not apply to newly seeded turf. Do not use on putting greens or collars. Note rate restrictions on perennial ryegrass. Rain after application reduces activity.
Site of action  Group 6: photosystem II inhibitor
Chemical family  Benzothiadiazole
•  chlorsulfuron (Corsair)
Rate  See label
Time  Apply when weed is actively growing.
Remarks  A dispersible granule herbicide intended primarily for spot treatment to eradicate tall fescue in established Kentucky bluegrass, fine fescue, and bentgrass as well as in some warm-season grasses. Irrigate thoroughly to activate herbicide.
Caution  Will kill perennial ryegrass. Treat only bentgrass mowed above 0.5 inch. Do not treat turf under stress from heat, drought, or other factors. Do not apply to saturated soils.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
•  halosulfuron-methyl (Sedgehammer)
Rate  See label
Time  Apply to well-established turfgrass when nutsedge is from the three- to eight-leaf stage
Remarks  A 75% WDG for selective postemergence control of purple and yellow nutsedge in established turfgrass. Treat nutsedge in the three- to eight-leaf stage. A second treatment may be required 6 to 10 wk later. Do not exceed 0.25 lb ai/A total or four applications per season. Use 0.5% nonionic surfactant concentration for broadcast applications.
Caution  Do not exceed 1 quart/A of surfactant; higher rates can injure turf. Use only nonionic surfactants with at least 80% ai. Do not mow turf for 2 days before or after application. Good results if no rain for 3 hr after application; best results if no rain for at least 4 hr after application. Turf must have a well-developed root system and a uniform stand before product is applied. Do not apply to putting greens or turfgrass under stress. Do not use clippings from treated turf as mulch around ornamentals.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  Sulfonylurea
•  mesotrione  (Tenacity)
Rate  See label
Time  Tenacity is a systemic preemergence and postemergence herbicide for the selective contact and residual control of weeds in turfgrasses. Applied preemergence, weeds absorb Tenacity during emergence. Dry conditions after application may reduce preemergence activity. If rain (0.15 inches) has not fallen within 10 days after a preemergence application, activate with 0.15 inches of irrigation. Used postemergence, susceptible weeds absorb Tenacity through foliar contact and soil absorption. Foliage of treated weeds stops growing after application, then turns white (loss of chlorophyll); and death may take up to 3 wk. A repeat application is required after 2 to 3 wk for improved postemergence weed control. Add a nonionic surfactant in postemergence applications. Tenacity may temporarily whiten turfgrass foliage. In general, symptoms appear 5 to 7 days after application and last several weeks. A repeat application to the same site causes less whitening of plant tissue. Tenacity effectively controls weed before or during seeding certain turfgrasses during turf renovation. Do not apply to newly germinated turfgrass until it has been mowed twice, or approximately 4 wk after emergence. Young, actively growing weeds are easiest to control. Efficacy on mature weeds is reduced under moisture stress. Tenacity can be tank-mixed with other herbicides, but check label for tank-mixtures already tested. Herbicides not listed on label as being tested for tank-mixtures must be tested for compatibility, safety, and efficacy before treating large areas. In established turf, Tenacity is more effective as a postemergence application unless combined with another soil active herbicide. Tenacity at 5 fl oz/A in at least 30 gal/A water in a 2- to 3-wk interval controls creeping bentgrass. Apply with an nonionic surfactant. Up to three applications can be made. Applications may be more effective in late summer/early fall, just before bentgrass renews growth, than in spring/early summer.
Remarks  For use on golf courses and sod farms. Do not use on golf greens. Maintain a 5-ft buffer between treated areas and putting greens. Do not exceed 5 fl oz/A per application to perennial ryegrass or fine fescues or mixed stands with more than 50% perennial ryegrass and/or fine fescue. Withhold traffic on treated areas until spray has dried and irrigate lightly to move product from turf foliage before resuming normal irrigation to prevent movement onto sensitive species such as bentgrass. Do not plant any crop other than turfgrass species for 18 mo after the last application of Tenacity, or injury may occur. Do not apply an organophosphate or carbamate insecticide within 7 days of a Tenacity application, as turf injury may occur. Do not apply by air or through any type of irrigation system. Do not exceed 16 oz/A Tenacity (0.5 lb mesotrione/A) per year. Restricted-entry interval is 12 hr.
Site of action  Group 27: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)
Chemical family  Triketone

Annual Grass Weed Control in Turf
Summer annual grasses are rarely a problem in western Washington or in the Willamette Valley and coastal areas of Oregon. They may be a problem in areas east of the Cascades throughout the Northwest and south of the Willamette Valley in Oregon, depending on local conditions. In controlling annual grasses, it is important to positively identify the grass before acting, to avoid wasting time and chemicals treating perennial grasses.
Preemergence herbicides are very effective in controlling crabgrass, barnyardgrass, foxtails, etc. if applied before these grasses germinate. If annual grasses are consistent problems, apply chemicals in spring when soil reaches 50° to 55°F, the temperature needed for germination. In some areas, this may coincide with late forsythia bloom. Irrigate after application of all preemergence herbicides to incorporate them into the soil where seed germination occurs. Once weedy grasses are observed, it is too late for preemergence control.
Annual grasses are generally difficult to control once they have infested turf. Selective postemergence control is best accomplished if annual grass seedlings are treated when they are small (i.e., five-leaf stage or younger).
TURFGRASS—Annual Grass Weeds
Preemergence
•  benefin (Crabgrass Preventer with 2.5% Balan herbicide)
Rate  See label
Time  Apply to established turfgrass before weed seeds germinate.
Remarks  Available in granular form for use on established turfgrasses. Effective on most annual grasses, including annual bluegrass. It kills seedlings as they germinate and has no postemergence activity. Benefin does not leach in most soils.
Caution  Water thoroughly after application to avoid loss of activity from photodecomposition. May injure closely cut bentgrass (turf).
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  bensulide (Bensumec 4LF or Pre-San Granular)
Rate  See label
Time  Apply to established turfgrasses on golf courses and residential lawns.
Remarks  Bensulide is available in granular and EC formulations. It is effective on most warm-season annual grasses and annual bluegrass. It kills seedlings by inhibiting root growth during germination and has no postemergence activity. Bensulide is unlikely to leach in most soils. It generally is safe on all established cool-season grasses on golf courses and residential lawns.
Caution  May stunt roots on putting turf if applied repeatedly or at excessive rates.
Site of action  Group 8: lipid synthesis inhibitor but not an ACCase inhibitor
Chemical family  Organophosphorus
•   (Dimension, Dynamo 40WSP, Dithiopyr 40SB)
Rate  See label
Time  Apply preemergence when soil is about 50°F (about when forsythia blooms). Apply postemergence before crabgrass and annual bluegrass are in first tiller stage.
Remarks  Dithiopyr is available in EC, 40WSB and 40WSP formulations, as granules, and on fertilizers. Gives preemergent control of crabgrasses, foxtails, barnyardgrass, and a number of broadleaf weeds, including purslane, Oxalis species, and spurge. Also gives preemergent control of annual bluegrass (Poa annua). Gives postemergence control of crabgrass up to the first tiller growth stage. Dithiopyr appears to be safe on mature creeping bentgrass, Kentucky bluegrass, perennial ryegrass, tall fescue, and some fine fescues.
Caution  Do not use on seedling turf; injury will be severe. Do not apply to turf under environmental stress.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Pyridine
•  ethofumesate (Prograss, Prograss EC Herbicide)
Rate  See label
Time  Apply to grasses listed as tolerant on label before annual bluegrass reaches the four-leaf stage.
Remarks  Available only as an emulsifiable concentrate (EC). Effective preemergent and early postemergent activity on many annual grasses and broadleaf weeds. Can use selectively in new seedings of perennial ryegrass to control annual bluegrass, which is susceptible from germination to the three- to four-leaf stage. Repeat fall treatments may control mature annual bluegrass in areas east of the Cascades. West of Cascades, ethofumesate has never successfully controlled mature annual bluegrass.
Caution  Severely injures most fine fescues. Mature hard fescue turf is more tolerant than Chewings or red fescue. Generally safe on perennial ryegrass, except on mature turf in spring when injury can be severe. Fall applications to bentgrass are highly phytotoxic. Bentgrass may be slightly injured at other times of year.
Site of action  Group 16: unknown
Chemical family  Benzofuran
•  benefin + trifluralin (Team 2G) 
Rate  See label
Time  Apply to established turfgrasses for preemergent annual grass control.
Remarks  Available only in granular form. The 2:1 ratio of benefin to trifluralin effectively controls summer annual grass and Poa annua. It kills seedlings as they germinate with no postemergence activity. Team does not leach.
Caution  Do not use on bentgrass mowed to less than 0.5 inch high. Irrigation or rain is required to activate the product.
Site of action  (both) Group 3: microtubule assembly inhibitor
Chemical family  (both) dinitroaniline
•  oxadiazon (Ronstar G or Ronstar 50WSP)
Rate  See label
Time  Apply to established Kentucky bluegrass and perennial ryegrass turf.
Remarks  Effective preemergent against most warm-season annual grasses, annual bluegrass, and some broadleaf weeds. Labeled only for use on mature Kentucky bluegrass and perennial ryegrass turf.
Caution  Phytotoxic to bentgrass and fine fescues. May injure Kentucky bluegrass and perennial ryegrass if applied to wet foliage.
Site of action  Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  Oxadiazole
•  mesotrione (Tenacity) 
Rate  See label
Time  Tenacity is a systemic preemergence and postemergence herbicide for selective contact and residual control of weeds in turfgrasses. Applied preemergence, weeds absorb Tenacity during emergence. Dry conditions after application may reduce preemergence activity. If rain (0.15 inch) does not fall within 10 days after a preemergence application, activate with 0.15 inch irrigation. Used postemergence, susceptible weeds absorb Tenacity through foliar contact and soil absorption. Foliage of treated weeds stops growing after application, then turns white (loss of chlorophyll); and death may take up to 3 wk. A repeat application is required after 2 to 3 wk for improved postemergence weed control. Added a nonionic surfactant in postemergence applications. Tenacity may temporarily whiten turfgrass foliage. In general, symptoms appear 5 to 7 days after application and last several weeks. A repeat application to the same site causes less whitening of plant tissue. Tenacity effectively controls weed before or during seeding certain turfgrasses during turf renovation. Do not apply to newly germinated turfgrass until it has been mowed twice, or about 4 wk after emergence. Young, actively growing weeds are easiest to control. Efficacy on mature weeds is reduced under moisture stress. Tenacity can be tank-mixed with other herbicides, but check label for tank-mixtures already tested. Herbicides not listed on label as being tested for tank-mixtures must be tested for compatibility, safety, and efficacy before treating large areas. In established turf, Tenacity is more effective as a postemergence application unless combined with another soil-active herbicide. Combine Tenacity with a preemergence herbicide for extended control of key annual monocot weeds such as crabgrass and foxtail.
Remarks  Use on golf courses and sod farms. Do not use on golf greens. Maintain a 5-ft buffer between treated areas and putting greens. Do not exceed 5 fl oz/A per application to perennial ryegrass or fine fescues or mixed stands with more than 50% perennial ryegrass and/or fine fescue. Withhold traffic on treated areas until spray dries, and irrigate lightly to move product from turf foliage before resuming normal irrigation, to prevent movement onto sensitive species such as bentgrass. Do not plant any crop other than turfgrass species for 18 mo after the last application of Tenacity, or injury may occur. Do not apply an organophosphate or carbamate insecticide within 7 days of a Tenacity application, as turf may be injured. Do not apply by air or through any type of irrigation system. Do not exceed 16 oz/A Tenacity (0.5 lb mesotrione/A) per year. Restricted-entry interval is 12 hr.
Site of action  Group 27: inhibits 4-hydroxyphenylpyruvatedioxygenase (4-HPPD)
Chemical family  Triketone
•  pendimethalin (Pre-M or Signature Fertilizer with 0.75% pendimethalin)
Rate  See label
Time  Apply before weed seeds germinate in spring.
Remarks  Available in emulsifiable concentrate (EC) and granular formulations. Controls most warm-season annual grasses, annual bluegrass, Oxalis species, and spotted spurge when applied preemergence. It is safe on most established cool-season turfgrasses.
Caution  Injures bentgrass and stains concrete and stone.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  prodiamine (Barricade, Halts Pro, Knighthawk Herbicide)
Rate  See label
Time  Apply before weed seeds germinate.
Remarks  Available as a 65% DF herbicide for use on established cool- and warm-season turfgrasses. Used properly, gives preemergent control of crabgrass, yellow foxtail, goosegrass, annual bluegrass, prostrate spurge, and several other weeds.
Caution  Water in thoroughly to avoid loss of activity from photodecomposition. Safe at label rates on tall fescue, Kentucky bluegrass, perennial ryegrass, creeping red fescue, and creeping bentgrass. Not intended for use on putting greens.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Dinitroaniline
•  prodiamine + sulfentrazone (Echelon 4SC) 
Rate  See label
Time  Apply for pre- and early postemergence control of crabgrass and for selective pre- and postemergence control of annual grasses, broadleaf weeds, and sedges in turf sites including residential and institutional lawns, athletic fields, commercial sod farms, golf course fairways and roughs, roadsides, utility right-of-ways, railways, and industrial areas.
Remarks  Existing weed roots and shoots take up Echelon; it also prevents growth of newly emerged weed seedlings. Echelon may be used on well-established seeded, sodded, or sprigged turfgrasses. Make first application after the second mowing, providing grass has developed into a uniform stand with a good root system. Applied as directed, creeping bentgrass, fine fescue, and perennial ryegrasses tolerate 0.25 to 0.375 lb ai/A of Echelon 4SC. Kentucky bluegrass and tall fescue tolerate 0.57 to 0.75 lb ai/A of Echelon 4SC. Do not exceed 1.125 lb ai/A per calendar year. Sulfentrazone has good activity on creeping buttercup.
Caution  Turf may be injured if it is not well established or has been weakened by stresses such as unfavorable weather, disease, chemicals, or mechanical influences. Do not apply to golf course greens and tees. Do not apply to areas where dichondra, colonial bentgrass, velvet bentgrass, or annual bluegrass are desirable species. Treated sod preharvest interval is 90 days. Do not apply with adjuvants or surfactants.
Site of action  (prodiamine) Group 3: microtubule assembly inhibitor; (sulfentrazone) Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  (prodiamine) dinitroaniline; (sulfentrazone) triazinone
•  siduron (Tupersan)
Rate  See label
Time  Apply for warm-season annual grass control at time of seeding of cool-season turfgrasses.
Remarks  Available in wettable powder (WP) and granular formulations. Safe on most cool-season turfgrasses. Can use on new seedings of cool-season grasses since it is active only against warm-season annual grasses. Will not control annual bluegrass.
Caution  May injure some bentgrass varieties. ‘Penncross’, ‘Seaside’, ‘Highland’, and ‘Astoria’ are tolerant.
Site of action  Group 7: photosystem II inhibitor
Chemical family  Substituted urea
Postemergence
•  dithiopyr (Dimension, Dynamo 40WSP, Dithiopyr 40SB)
Rate  See label
Time  Apply to established turf before crabgrass begins tillering.
Remarks  Controls crabgrass postemergence if applied before crabgrass produces tillers. After tillering, dithiopyr must be mixed with either MSMA or fenoxaprop to achieve acceptable control.
Caution  Do not use on seedling turf or turf growing under environmental stress.
Site of action  Group 3: microtubule assembly inhibitor
Chemical family  Pyridine
•  MSMA 
Rate  See label
Time  Apply to established turfgrass for annual grass control.
Remarks  Available in liquid formulations. Arsenicals are generally effective but may require two applications at 10- to 14-day intervals to achieve complete control.
Caution  Arsenicals may injure bentgrass and fine fescues. Soil should be moist but not saturated at time of treatment.
Site of action  Group 17: not well understood
Chemical family  Organoarsenical
•  fenoxaprop (Acclaim Extra) 
Rate  See label
Time  Apply to established turfgrasses for specific annual grasses listed on label. Grasses controlled include smooth and large crabgrass, goosegrass, barnyardgrass, foxtail species, Panicum species, Johnsongrass (seedling) , sandbur, sprangletop, and Japanese stiltgrass.
Remarks  Available as an emulsifiable concentrate (EC). It is effective as a postemergent warm-season annual grass herbicide and is safe on most cool-season turfgrasses. It is foliar absorbed, slow acting and should be applied with 40 to 80 gal/A for thorough coverage. Do not mow areas for 24 hr after application to allow penetration and translocation into the grassy weeds. Grass clippings can interfere with thorough spray coverage of the target weeds. 
Caution  Weed control may be reduced if fenoxaprop is mixed with common broadleaf herbicides. Fenoxaprop may injure Kentucky bluegrass and bentgrasses. Repeat applications may be needed for control. Do not exceed a total of 120 fl oz/A per growing season. If turfgrass was stunted after a previous application, avoid applying again until turfgrass completely recovers.
Site of action  Group 1: acetyl CoA carboxylase (ACCase) inhibitor
Chemical family  Aryloxyphenoxy propionate
•  sulfosulfuron (Certainty Turf Herbicide) 
Rate  See label
Time  Apply postemergence when target weeds are actively growing and not disturbed by mowing for at least 2 days after application.
Remarks   A postemergence, systemic herbicide with limited soil residual activity. Gives postemergence control of many annual and perennial sedges, grass and broadleaf weeds on highly managed turf, sod farms, and native grass sites. A selective herbicide that can be used over the top of many perennial warm-season and selected cool-season turfgrasses. Recommended for use on creeping bentgrass, Kentucky bluegrass, and Kentucky bluegrass mixtures with perennial ryegrass and/or fine fescue. Apply only when grasses are actively growing and mowing is required. Product can control roughstalk bluegrass (Poa trivialis). Can apply to residential and commercial turf sites, including apartment complexes, athletic fields, cemeteries, golf course fairways, tees, and roughs, hotel properties, office complexes, parks, public turf areas, retail sites, storage facilities, school grounds, sod and turfgrass seed farms, and other highly managed turfgrass areas. Product is absorbed by both roots and foliage and rapidly inhibits susceptible weeds, whose growth stops within 24 hr of treatment even though visual symptoms are slow to develop. Susceptible weeds usually show yellowing or browning within 2 to 3 wk. Warm, moist conditions after application accelerate herbicidal activity; cold, dry conditions delay activity. Weeds stressed by drought are less susceptible. 
Caution  DO NOT apply directly to or within 4 ft of golf course putting greens. Using this chemical on permeable soils, particularly where the water table is shallow, may contaminate ground water. Heavy rain or irrigation within 2 hr after application may wash product off the foliage, and a repeat application may be required for adequate control. Do not exceed a total of 2.66 oz/A per year. Avoid contact with roots or foliage of susceptible nontarget vegetation; injury may occur. This includes areas where product may be washed or moved into contact with roots of desirable vegetation. Susceptible plants may be injured if seeded or transplanted into treated areas unless otherwise directed on label. Applications in fall, after temperatures drop and regular mowing is no longer required, may increase risk of turf injury and may delay spring green-up. Applications may result in temporary chlorosis and discoloration and may affect desirable turf’s growth pattern; symptoms generally appear 7 to 10 days after application and typically go in 21 to 28 days. Perennial ryegrass, fine fescues, and creeping bentgrass are more sensitive to this product.
Site of action  Group 2: acetolactate synthase (ALS) inhibitor
Chemical family  sulfonylurea

Chemical Renovation of Turfgrass
Old turf areas eventually are invaded and often dominated by naturalized grasses including bentgrasses, roughstalk bluegrass, annual bluegrass, velvetgrass, tall fescue, quackgrass, and bermudagrass. Managers who desire pure turf stands need to renovate periodically by killing all vegetation and reseeding.
Most attempts at chemical renovation fail outright or provide only short-term control of weedy grasses. For good results, managers must completely kill weeds and prevent reinfestation from seed. To optimize kill of weedy grasses, leave the target turf unmowed for several weeks as it grows vigorously. In spring, the best time to spray cool-season grasses is at early flowering, to maximize kill of difficult grasses such as velvetgrass, bentgrass, and tall fescue. In fall, spray turf when new growth is at least 3 inches tall. Summer sprays often are ineffective due to poor translocation to crowns and rhizomes. Remember, good foliar kill does not always mean complete plant kill.
On renovation sites replanted with straight perennial ryegrass, a selective preemergent herbicide containing ethofumesate can be applied to control germinating annual bluegrass. Applied properly, ethofumesate gives 90 to 100% control of germinating annual bluegrass with no harmful effects on the developing ryegrass turf. 
TURFGRASS—Chemical Renovation and Combination Products for Extended (6 mo) Bare Ground (Edging)
Nonselective postemergence
•  glufosinate (Finale)
Rate  See label
Time  Apply when weeds are actively growing.
Remarks  A nonselective contact herbicide. Treated plants show distinct yellowing generally within 3 days after treatment. Controls annual grasses and broadleaf weeds. Suppresses biennial and perennial weeds by destroying green foliage.
Caution  Use caution in spraying turf near ornamental plantings, which may be injured or killed by drift or direct spray contact.
Site of action  Group 10: glutamine synthase inhibitor
Chemical family  Phosphinic acid
•  glyphosate (Accord XRT II, Deal Glyphosate herbicide, Durango DMA herbicide, Roundup PRO, Roundup PRO Dry, Roundup ProMax, Mon 006 herbicide, or several other products)
Rate  See label
Time  Apply when target plants are actively growing.
Remarks  Properly applied, glyphosate kills all common weedy grasses and many broadleaf weeds. Results on grasses are best if turf is allowed to grow at least 3 inches tall or to flower. For maximum kill, delay replanting to see whether regrowth is from crowns or rhizomes. Bermudagrass kill is better with summer or early fall sprays. Roundup PRO is for use in industrial (nonagricultural) markets. Roundup PRO has a new formulation of surfactants with a Category IV acute toxicity rating and “Caution” signal word. It contains 15% surfactant for faster activity and is rainfast in 1 to 2 hr. Effects on weedy grasses are visible in 2 to 4 days but on most perennial weeds not for 7 days or more. Roundup PRO’s active ingredient inhibits an enzyme essential for forming specific amino acids. Roundup PRO Dry is a water-soluble granule containing surfactant; no additional surfactant is needed or recommended.
Caution  Avoid tilling or slice-seeding sprayed areas for at least 7 days to ensure adequate translocation to crowns, rhizomes, and roots. Use caution in spraying turf near ornamentals, which may be injured or killed by drift or direct spray contact. See label for site application for each product.
Site of action  Group 9: inhibits EPSP synthase
Chemical family  None generally accepted
•  glyphosate (Glypro Plus)
Rate  See label
Time  Apply when plants are actively growing to get best results.
Remarks  Suppresses perennial grasses (see label for specific grasses and rates) and can substitute for mowing. Also can suppress annual rye, wild barley rye, and wild oat in coarse turf on roadsides or in industrial areas. Use only if some damage or discoloration of perennial grasses can be tolerated. Glypro Plus controls most existing vegetation prior to renovating turfgrass or establishing turfgrass from seed or sod. If existing vegetation is being mowed, omit at least one regular mowing before application to allow sufficient growth to intercept the spray well.
Caution  Avoid herbicide contact with foliage, green stems, exposed nonwoody roots or fruit of crops, and desirable plants and trees; severe injury or death may result. Do not treat weeds under poor growing conditions such as drought stress, disease or insect damage; weed control may be reduced. Herbicide activity may also be reduced if weeds are very dusty. Do not disturb soil for 7 days after application. Do not feed or graze turfgrass grown for seed or sod production for 8 wk after applying.
Site of action  Group 9: inhibits EPSP synthase
Chemical family  None generally accepted
•  glyphosate + carfentrazone-ethyl (Rage) 
Rate  See label
Time  Weed control is best when product is applied to actively growing weeds up to 4 inches high or rosettes less than 3 inches across.
Remarks  Rage is a broad spectrum, nonselective herbicide, providing both contact and systemic herbicide effects. Rage herbicide’s two modes of action help minimize herbicide-resistant weed populations. It is a liquid emulsion formulation (EW). Mix with water and a recommended adjuvant to control selective postemergence broadleaf and grass weeds on labeled crops. Rage is absorbed rapidly through plant foliage and is rainfast when spray solution dries. To avoid significant crop response, do not apply within 6 to 8 hr of either rain or irrigation. Within a few hours of application, foliage of susceptible weeds shows signs of desiccation. Plant necrosis and death occur several days after the application. Weeds hardened by droughty conditions are less susceptible.
Caution  Product is only for use by individuals/firms certified and/or licensed as pesticide applicators. Large droplet size limits drift. A nonionic surfactant, methylated seed oil, or crop oil concentrate is required for use. See label for specifics.
Site of action  (glyphosate) Group 9: inhibits EPSP synthase; (carfentrazone-ethyl) Group 14: protoporphyrinogen oxidase inhibitor
Chemical family  (glyphosate) none generally accepted; (carfentrazone-ethyl) triazinone
Nonselective postemergence and preemergence
•  glyphosate + prodiamine (ProDeuce) 
Rate  See label
Time  Apply to both established weeds and weed-prone areas before weeds emerge; for example, treat cracks and crevices in driveways, fencelines, foundations, curbs, retaining walls, or lawn edges. Glyphosate enters through foliage and moves systemically to roots, killing weeds by stopping production of a substance found in plants. Weeds begin to yellow and wilt in a matter of days; kill is complete in 1 to 2 wk. Prodiamine provides an invisible barrier in soil by preventing growth and development of newly germinated weeds. Spray when air is calm to prevent drift to desirable plants. For best results, apply during warm, sunny weather (above 60°F).
Remarks  All plants, trees, shrubs, sod and seed may be planted 6 mo after application when applying at the 3-oz/1,000 sq ft rate. 
Caution  Stay off treated areas until sprays are dry. Take care to prevent tracking product onto desirable grasses. Do not spray desirable plants. Do not use in lawns for lawn renovations, because product will prevent desirable grass establishment for up to 6 mo. Do not apply with a galvanized or unlined steel (except stainless steel) sprayer, or through any irrigation system.
Site of action  (glyphosate) Group 9: inhibits EPSP synthase; (prodiamine) Group 3: microtubule assembly inhibitor
Chemical family  (glyphosate) none generally accepted; (prodiamine) dinitroaniline
•  pelargonic acid (Scythe)
Rate  See label
Time  For best results, apply when plants are actively growing and day is sunny and warm.
Remarks  A nonvolatile, contact, nonselective, broad-spectrum, foliar-applied emulsifiable concentrate (EC). It is nonsystemic with no soil residual and will not move through soil. Controls both annual broadleaf and grass weeds less than 6 inches high. Suppresses biennial and perennial weeds by destroying green foliage. Effects are visible within hours. Does not damage woody plant parts. Can be used to spot-weed or edge turf and landscape areas. Spray to wet but not to the point of runoff. Cool or cloudy weather after treatment may slow activity and delay visible effects.
Caution  Avoid spray contact with foliage of desirable turfgrasses, trees, shrubs, or other vegetation because damage may result.
Site of action  Group 26: unknown
Chemical family  Carboxylic acid
Selective preemergent and early postemergent
•  ethofumesate (Prograss, Prograss EC Herbicide)
Rate  See label
Time  Apply to grasses listed as tolerant on label before annual bluegrass reaches the four-leaf stage.
Remarks  Ethofumesate is available only as an emulsifiable concentrate (EC). It provides effective preemergent and early postemergent control of annual bluegrass in new seedings of perennial ryegrass. It is root absorbed; water it in after application.
Caution  Ethofumesate inhibits germination of most desirable cool-season grasses other than perennial ryegrass. It is highly toxic to seedling fine fescues. Surface organic matter decreases its effectiveness. Remove thatch and other debris before applying.
Site of action  Group 26: unknown 
Chemical family  Benzofuran

Susceptibility of Broadleaf Weeds in Turf 
to Common Herbicides

Weed	2,4-D	dicamba	MCPP	MCPA	Mixtures
with
triclopyr	Mixtures
without
triclopyr	
Bindweed, field 
Convolvulus arvensis	S-I	S	I	—	S	S	
Buttercup, creeping* 
Ranunculus repens	S-I	S-I	I	S-I	—	I	
Carrot, wild 
Daucus carota	I	S	I	—	—	S	
Chicory 
Cichorium intybus 	S	S	S	—	S	S	
Chickweed, common 
Stellaria media	R	S	S-I	—	S	S	
Chickweed, mouseear 
Cerastium vulgatum	I-R	S	S-I	—	S	S	
Clover, hop 
Trifolium spp.	I	S	S-I	I	S	S	
Clover, subterranean 
Trifolium subterraneum	I	S	I	I	S	S	
Clover, white 
Trifolium repens	I	S	S-I	I	S	S	
Cranesbill 
Geranium carolinianum 	S-I	S	S-I	—	S	S	
Daisy, English** 
Bellis perennis	R	I	I	—	S	S-I	
Daisy, oxeye 
Chrysanthemum leucanthemum	I	I	I	—	—	S-l	
Dandelion, common 
Taraxacum officinale	S	S	S-I	S-I	S	S	
Dandelion, false 
Hypochoeris radicata	S	I	R	—	S	S	
Healall 
Prunella vulgaris 	S-I	S	S-I	—	I	S	
Henbit 
Lamium amplexicaule 	I-R	S	I	—	S	S	
Ivy, ground 
Glechoma hederacea	I-R	S-I	I	—	S	R	
Knotweed, prostrate 
Polygonum aviculare	I-R	S	I	—	S	S	
Lambsquarters 
Chenopodium album 	S	S	S	S	S	S	
Medic, black 
Medicago lupulina 	I-R	S-I	I	—	S	S-I	
Mustard, wild 
Brassica kaber	S	S-I	I	S	S	S	
Pearlwort 
Sagina procumbens 	I-R	S	S	—	—	S	
Pigweed, prostrate 
Amaranthus blitoides	S	S	S	S	S	S	
Pineappleweed 
Matricaria matricarioides 	I-R	I	I	—	—	I	
Plantain, broadleaf 
Plantago major	S	R	I	I	S	S	
Plantain, buckhorn 
Plantago lanceolata	S	R	I	I	S	S	
Purslane, common 
Portulaca oleracea	I	S	R	I	S	S	
Shepherdspurse 
Capsella bursa-pastoris 	S	S	S-I	S	S	S	
Sorrel, red 
Rumex acetosella	I-R	S	R	—	—	S	
Speedwells*** 
Veronica spp.	R	R	R	—	R	R	
Spurge, prostrate 
Euphorbia supina	I	S-I	I	—	S	S-I	
Thistle 
Cirsium spp. 	S-I	S	I	I	S	S	
Violet, wild 
Viola spp.	I-R	I-R	I-R	—	S	I-R	
Woodsorrel, yellow 
Oxalis corniculata	R	I	I-R	—	S	I-R	
Yarrow, common 
Achillea millefolium	I	S	I-R	—	S	S-I	
S = susceptible; I = intermediate (may require several successive applications for control); R = resistant
*Sulfentrazone will give good control of buttercup. 
**Penoxsulam gives good control of English daisy. 
***Mixtures with triclopyr may control Veronica chamaedrys. Quinclorac will control English daisies and common, slender, and thymeleaf speedwell with one application. See label for seed oil or crop oil additive rates to use with quinclorac.