Best Management Practices:
Crabgrass is a warm season, annual grassy weed that normally has dense hair on the leaves and a finger-like seedhead with two to nine thin branches. Crabgrass only comes back from seed each year, usually germinating in the early spring season.
Pre-emergent herbicides work by killing germinating seeds from weedy plants like crabgrass. Normally, an application of a pre-emergent in mid/late February will work well. Remember, though, that this weed may germinate into the summer—so, a second pre-emergent application in early May is usually warranted.
There are several pre-emergent herbicides that can be used to control crabgrass in most turfgrass sites including bermudagrass, St. Augustinegrass, zoysiagrass, and buffalograss. Examples include: XL- 2G (Benefin plus Oryzalin), Pendulum 2G or Anderson 11-3-11 (Pendimethalin), Crabgrass Control and Balan 2.5 G (Benefin).
These herbicides can be effective if used when the crabgrass is very young/immature and actively growing. Examples of effective products are Image 70 DG, Crab-E-Rad Plus or Drive 75 DF Herbicide (Quinclorac). It may require multiple applications to obtain excellent control with these post-emergent products. CAUTION: Crab-E-Rad and Drive can only be used on bermudagrass and zoysiagrass turf sites---NOT ST. AUGUSTINEGRASS! If you do decide to spot spray with these post-emergent herbicides in St. Augustinegrass, you can expect at least some damage to the surrounding St. Augustinegrass unless you are extremely careful not to get any on your turf. Make sure there is no wind to avoid drift and set your sprayer to where the droplet size is much larger (not a fine mist).
Best Management Practices courtesy of:
Bes-Tex Supply, LLC P.O. Box 664 San Angelo, Texas 76902 Ph. 325-653-1300