Now that the lawn and weeds have greened-up from the recent rains, broadleaf herbicides should be effective yet this fall. Though these herbicides work faster when the plants are actively growing, these herbicides will still work as long as the plants are green and photosynthesizing. Therefore, applications into November will work, albeit slower. You may not even see any effect this year, but weeds will die over the winter. However, herbicides that contain carfentrazone (FMC’s Quicksilver, PBI Gordons’ Powerzone and Speedzone) will still give a response in 7 to 10 days even when applied in late October or early November. To maximize success with any broadleaf herbicide, try to apply on a dry, warm (>550F), sunny day to maximize effect. If you have problems with winter annual broadleaf weeds such as common chickweed, it makes more sense to apply a broadleaf herbicide as late as possible in the fall to control most of these late-germinating weeds. This would be especially important on fall seedings that may be struggling because of weed cover right now. More information on late fall broadleaf weed control can be found in Turf Tips from Aug. 9, 2004.