Roch Gaussoin, professor and extension specialist, writing for the University of Nebraska’s Turf iNfo, said: “This time of year, especially in turf thinned by drought, disease, traffic or other afflictions, crabgrass and other summer annuals may pop up, even if the turf was treated with an effective preemergence product. No product is 100% effective even when applied correctly “Escapes” may occur for a number of reasons including misapplication. Regardless of the reason or type of turf area, older and larger crabgrass is much more difficult to control than younger plants, making mid-season the optimal time to control crabgrass post emergence. Waiting to treat when the crabgrass is more visible and tillering will result in the need for higher herbicide rates, increased risk of damage to desired turf and decreasing control.
Drive and other quinclorac-containing products will control young crabgrass effectively as long as the appropriate spray adjuvant is used. Tenacity, Acclaim (fenoxaprop), NuFarm’s Last Call (fenoxaprop + fluroxypyr), or BASF’s Pylex will control crabgrass as well as other weeds listed on the label. Be sure to check the label for specific species, rates, and precautions (including overseeding limits) as well as the need for a spray adjuvant.”