Controlling winter weeds (03-14-05)

What can we do about all those winter weeds in our yards now? Most of these weeds are what we term as “winter annuals”. Many of these weeds will die shortly when the temperatures finally warm up and stay there. They are flowering heavily now, which is why you see the bright purples, yellows, and whites in the landscape. Since they are flowering and into a reproductive stage, there is really little point in spraying most of these species now. They are completing their life cycle and will be dying soon anyway.

Probably the best remedy is to simply mow them to remove most of the leaf and flower canopy and vow to use a preemergence herbicide late next summer or early fall to prevent their prodigy from germinating next year. There are only one or two species, such as lawn burweed (sticker weed), that if the tiny stickers have not yet formed, still warrant spraying now.

One other adverse problem many of them will provide is that as they die they will leave small openings in the canopy of the permanent turf for a while so “summer annuals” such as crabgrass, goosegrass, prostrate spurge and the like may take their place if a preemergence herbicide is not applied this spring.

There are a few perennial winter weeds that you may want to control now such as wild garlic, dandelions, clover, plantains, etc. so broadleaf post-emerge herbicides such as 2,4-D, dicamba, mecoprop, clopyralid, metsulfuron, and others may be used effectively.

For further information on specific herbicides look for the Extension publication “Weed Control Guidelines for Mississippi” on this web site.

Published March 14, 2005

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. wwells@ext.msstate.edu