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Table 4. Suggestions for selective control of turfgrass weeds in Pennsylvania, by weed species.

Table 4. Suggestions for selective control of turfgrass weeds in Pennsylvania, by weed species.*
Weed Material Apply Remarks
*Suggestions for specific herbicides are based on product label information and performance in a limited number of research trials. Because herbicide effectiveness can vary with environmental conditions, location, and methods of application, suggestions listed in this table may not completely conform to the turfgrass safety and weed control standards indicated by research trials.
Annual Bluegrass Poa annua bensulideor Late summer Apply just prior to expected annual bluegrass germination (late August or early September). Effectiveness of control varies. Only effective in reducing populations of the annual subspecies of annual bluegrass.
or

ethofumesateor
September and October For use on established perennial ryegrass or Kentucky bluegrass or when establishing perennial ryegrass. Two applications are necessary. Do not mix with liquid fertilizers or other pesticides. Also labeled for bentgrass fairways.
or

paclobutrazol or flurprimidol
See remarks Use for gradual conversion from annual bluegrass to bentgrass in golf course fairways through selective growth retardation. Follow label directions for application timing and rates.
Black Medic Medicago lupulina Clopyralid, or fluroxypyr, or dicamba, or quinclorac, or combination of products containing clopyralid or dicamba, or 2,4-D + triclopyr Spring or fall Best control when weeds are actively growing. Products containing carfentrazone provide faster burndown of black medic than those without carfentrazone.
Chickweed: Common
Stellaria media
Mouse ear
Cerastium vulgatum
MCPP, or dicamba, or combination of products containing MCPP and dicamba, or clopyralid + triclopyr, or 2,4-D + triclopyr Spring or fall Best control when weeds are actively growing.
Chicory Cichorium intybus 2,4-D, or combination of products containing 2,4-D or MCPA Spring Most effective on young weeds.
Cinquefoil Potentilla spp. 2,4-D + MCPP + dicamba, or 2,4-D + dicamba, or 2,4-D + triclopyr Spring Difficult to kill. May require repeat applications.
Clover Trifolium spp. Clopyralid, or fluroxypyr, or dicamba, or quinclorac, or combinations of herbicides containing clopyralid or dicamba, or 2,4-D + triclopyr Spring, summer, or fall Best control when weeds are actively growing. Combinations of herbicides containing carfentrazone provide faster burndown of clover than those without carfentrazone.
CORN CHAMOMILE Anthemis arvensis DOG FENNEL Anthemis cotula PINEAPPLE WEED Matricaria spp. 2,4-D + MCPP + dicamba, or 2,4-D + dicamba Spring, summer, or fall Best control when weeds are actively growing.
Crabgrass: Small (smooth) Digitaria ischaemum Large (hairy) Digitaria sanguinalis Preemergence control: benefin, or benefin + trifluralin, or bensulide, or bensulide + oxadiazon, or dithiopyr, or oxadiazon, or pendimethalin, or prodiamine, or siduron Early to mid-spring Best controlled if herbicides are applied about 2 weeks prior to expected crabgrass germination. Crabgrass normally germinates when soil temperatures near the surface reach 55°–58°F for several consecutive days. Herbicides are more effective when watered in following application. Check labels for nontolerant species and cultivars. Check labels for intervals until overseeding can take place. Seeding of desirable grasses may be made at the time of or immediately before the application of siduron. Effectiveness of some herbicides on established turf may be enhanced by a second application if the label specifies that a second application is allowed.
Postemergence control: Fenoxaprop-p-ethyl, or methanearsonates (DSMA or MSMA), quinclorac, or dithiopyr Early summer Apply postemergence products only when crabgrass is visible in the stand. Apply fenoxaprop-p-ethyl only when soil moisture is adequate and crabgrass is or actively growing. This herbicide may temporarily discolor some Kentucky bluegrass cultivars and is less effective if tank-mixed with phenoxy herbicides. Methanearsonates may injure desirable turfgrass species at high temperatures (greater than 80 °F). Apply quinclorac before development of second tiller or when crabgrass plants have five or more tillers. In some cases, quinclorac does not provide complete control of crabgrass at the two-, three-, and fourtiller stages of development. Quinclorac can be mixed with other herbicides, including phenoxys, to improve weed control. Dithiopyr controls crabgrass postemergence only up to tiller initiation.
Creeping Buttercup Ranunculus repens 2,4-D + dicamba, or 2,4-D + triclopyr, triclopyr + clopyralid, or 2,4-D + MCPP + dicamba, or 2,4-D + 2,4-DP + dicamba, or 2,4-D + 2,4-DP Spring or fall Difficult to kill. May require repeat applications.
Curly Dock Rumex crispus 2,4-D + dicamba, or 2,4-D + MCPP + dicamba, or 2,4-D + triclopyr Spring to early summer Mature plants difficult to kill.
Dandelion Taraxacum officinale 2,4-D, or 2,4-D + MCPP + dicamba, or 2,4-D + 2,4-DP + dicamba, or 2,4-D + 2,4-DP, or 2,4-D + triclopyr Spring or fall May require spring and fall applications.
Goosegrass (silver crabgrass) Eleusine indica Preemergence control bensulide + oxadiazon, or oxadiazon, or pendimethalin Late spring to early summer Herbicides are more effective when watered in following application. Check labels for nontolerant species and cultivars and for intervals until overseeding can take place.
Postemergence control Fenoxaprop-p-ethyl Early summer Fenoxaprop-p-ethyl should be applied only when there is adequate moisture and goosegrass is actively growing. This herbicide may temporarily discolor some Kentucky bluegrass cultivars and is less effective if tank-mixed with phenoxy-type herbicides.
Ground Ivy Glechoma hederacea 2,4-D + MCPP + dicamba, or triclopyr and clopyralid, or 2,4-D + triclopyr Early spring or fall. Fall applications are most effective if made after first frost. Extremely difficult to kill. Repeat applications will reduce, but may not completely eliminate, this weed.
Hawkweed Heracium spp. 2,4-D + dicamba, or 2,4-D + MCPP + dicamba, or MCPA + MCPP + dicamba Early spring or fall Repeat applications may be necessary. Control may be improved with a wetting agent (check herbicide label to see if a wetting agent is allowed). Thoroughly wet the plant. Accompany with adequate lime and fertilizer treatment.
Heal-All Prunella vulgaris 2,4-D + MCPP + dicamba Early spring or fall Difficult to kill. Repeat applications may be needed.
Henbit Lamium amplexicaule 2,4-D + dicamba, or 2,4-D + 2,4-DP, or 2,4-D + MCPP + dicamba, or triclopyr + clopyralid, or 2,4-D + triclopyr Spring Difficult to control. Treat weeds when young; repeat applications may be necessary.
Knotweed Malva spp. 2,4-D + MCPP + dicamba, or 2,4-D + triclopyr, or 2,4-D + 2,4-DP, or 2,4-D + 2,4-DP + dicamba Spring Extremely difficult to kill. May require repeat applications.
NUTSEDGE, YELLOW Cyperus esculentus Bentazon or halosulfuron When weeds are actively growing in late spring or early summer Do not apply to newly seeded turfgrass. Avoid mowing 3–5 days before and after applying bentazon and halosulfuron. Bentazon may injure ryegrasses.
PLANTAINS: Broadleaf Plantago major Buckhorn Plantago lanceolata Rugel’s Plantago rugelii 2,4-D, or 2,4-D + MCPP + dicamba, or 2,4-D + 2,4-DP + dicamba, or 2,4-D + triclopyr, or triclopyr + clopyralid, or MCPA + MCPP + dicamba Spring or fall Best control when weeds are actively growing.
Purslane Portulaca oleracea 2,4-D + MCPP + dicamba, or 2,4-D + triclopyr When actively growing Difficult to kill; repeat applications may be needed.
Sheep Sorrel (red sorrel)Rumex acetosella 2,4-D + 2,4-DP + dicamba, or dicamba, or 2,4-D + MCPP + dicamba, or triclopyr + clopyralid, or MCPA + MCPP + dicamba Spring, summer, or early fall Apply lime and fertilizer as needed.
Shepherd's Purse Capsella bursapastoris MCPP, or dicamba, or 2,4-D + MCPP + dicamba, or triclopyr + clopyralid, or MCPA + MCPP + dicamba Spring or fall Best control when weeds are actively growing.
Prostrate Spurge Euphorbia supina Postemergence control: dicamba, or 2,4-D + MCPP + dicamba, or MCPA + MCPP + dicamba When weeds are actively growing Spurge is difficult to kill; may require repeat applications.
Preemergence control: pendimethalin, or benefin + trifluralin, or prodiamine Early to mid-spring
Speedwells:
Creeping Veronica filiformis 2,4-D + triclopyr, or quinclorac Mid- to late May Extremely difficult to control; repeat applications may be necessary.
Corn or rock Veronica arvensis Postemergence control: 2,4-D + MCPP + dicamba,or 2,4-D + triclopyr Spring or summer Extremely difficult to control; repeat applications may be necessary.
Preemergence control: Oxidiazon Late summer Apply in August before weeds germinate.
Thyme-leaved Veronica serpyllifolia 2,4-D + MCPP + dicamba Spring Extremely difficult to control; complete control unlikely. Be sure lime and fertilizer needs are met.
Other speedwells Veronica spp. 2,4-D + MCPP + dicamba Spring or summer Difficult to control.
Violets Viola spp. 2,4-D + 2,4-DP, or 2,4-D + 2,4-DP + dicamba, or triclopyr + clopyralid, or 2,4-D + triclopyr May Limited effectiveness; repeat applications usually necessary.
WILD CARROT Daucus carota 2,4-D, or 2,4-D + dicamba, or 2,4-D + MCPP + dicamba, 2,4-D + triclopyr Early spring or fall Apply to young plants or when plants are actively growing.
Wild Garlic
Allium vineale
Wild Onion

Allium canadense
2,4-D, or 2,4-D + MCPP + dicamba, or 2,4-D + 2,4-DP + dicamba Spring, when garlic and onions are actively growing Requires treatment annually for several years. Use ester formulation, wet plants thoroughly.
Wild Geranium (cranesbill)Geranium spp. 2,4-D + MCPP + dicamba, or MCPA + MCPP + dicamba Spring Difficult to kill. May require repeat applications.
Woodsorrel, Yellow Oxalis spp. 2,4-D + 2,4-DP, or 2,4-D + 2,4-DP + dicamba, or 2,4-D + triclopyr, or triclopyr + clopyralid Summer or fall Difficult to kill. May require repeat applications.
Yarrow Achillea millefolium 2,4-D + dicamba, or 2,4-D + MCPP + dicamba, or 2,4-D + 2,4-DP + dicamba, or 2,4-D + MCPP + dicamba, or 2,4-D + triclopyr Spring Best control when weeds are actively growing.
Yellow Rocket (wintercress) Barbarea vulgaris 2,4-D, or 2,4-D + MCPP + dicamba Spring Best control when weeds are actively growing.