Optimal Application Time To Apply Pendimethalin Next Year?

Q: Your recent article on stiltgrass recommended to use a pre-emergent. Can you give the optimal application time to apply pendimethalin next year? 

A: Pendimethalin will control stiltgrass if it is applied before its seeds germinate in spring. Stiltgrass seed germinate before crabgrass seed and they continue sprouting into early summer. I recommend a half-strength application of pendimethalin in mid-February and a second half-strength application in mid-May.