In early fall, the favorable growth period is just beginning and weed problems are fewer. If you've resolved to address chronic lawn weed problems in 1998, consider several factors. First, sound cultural practices, such as proper mowing, fertilizing, and watering will keep lawns healthy and weed problems to a minimum. When using herbicides, application timing is critical to assure good control and minimum pesticide use. For crabgrass, the target date for preemergence crabgrass herbicides is about the first week of May. Broadleaf weeds, such as dandelions, are often best controlled in early fall, although late spring applications can be effective.
Most thatch problems originate in the soil, either compaction or poor drainage.
For this reason, core aerification is a suggested way to manage thatch problems.