The recent rains in eastern Kansas, along with the cooler fall temperatures, make this an excellent time to chemically control cool-season broadleaf weeds such as dandelion.
The key is to apply the chemical when the weeds are actively growing in their vegetative growth cycle -- when they are not flowering. During the vegetative cycle of the weed, more assimilates are transported to the root system. Herbicides applied at this time are more likely to reach the roots, resulting in death of the entire plant.
When dandelions or other weeds are flowering, less of the herbicide reaches the root system and often the weed is only injured rather than completely killed. That is why chemical control of dandelions in the spring is not as effective.
An additional benefit of fall control is that trees and shrubs are less susceptible to injury from spray drift.
Products containing 2,4-D alone or with other herbicides will give effective control of dandelions and other broadleaf weeds. Products containing a combination of 2,4-D, MCPP and dicamba (Trimec) will give the broadest control.
Check and follow label instructions carefully. Be aware that many products, including some formulations of Trimec, are not labeled for use on buffalo grass.
Remember that the best weed control is a healthy, dense turf. Proper mowing, watering and fertilizing will thicken the turf and reduce the need for herbicides.
-- The Garden Calendar is sponsored by the Douglas County Extension Service and is written this week by Extension Director Dennis D. Bejot. For more information, call the Extension Office, 843-7058, from 8 a.m. to 5 p.m., Monday through Friday.