A website from UGA Cooperative Extension

As winter settles in, many homeowners might think their lawn care duties are complete. However, this is the perfect time to prevent those pesky yellow and purple flowers that often carpet lawns in early spring. We always end up receiving calls from frustrated homeowners about this issue, we want to address this common concern before the calls start flooding in.  

We are already starting to notice winter annual weeds emerging. These are not just any weeds – they are the same ones that will create those carpets of purple henbit and yellow dandelions that prompt so many calls to our office come springtime. Timing is everything; once winter annuals begin flowering, they become significantly harder to control.  

The key to successful weed control is acting before those unwanted plants reach maturity. Being in the beginning of the year, these winter annuals are already germinating in your lawn. However, fall and early winter treatment can significantly reduce spring weed problems.  

Let us be realistic – between fall activities and holiday commitments, weed control might slip your mind. If you find yourself in January with emerging weeds, do not panic, you still have options. For those of you with either bermudagrass or zoysia you have some options as well. All products advertised for crabgrass control can be used to control several winter annuals.  Products with active ingredients such as pendimethalin, oryzalin, and benefin are good products that will control annual bluegrass, chickweed, and henbit.  Dithiopyr, which is in Turf & Ornamental Weed & Grass Stopper, controls a few more weed species, but might be harder to find.  For longer control a 2nd application may be necessary.  

If you have Centipede or St. Augustine, you could apply Atrazine to control most annual broadleaf weeds, some perennial weeds, and annual bluegrass.  This is an effective treatment that provides both pre- and post-emergence control.  This means that it will kill a lot of what has emerged and keep a lot of other weeds from ever emerging.  With Atrazine care must be taken to not over apply because it can damage desired grass species.  It also should not be used in the root zone of trees and shrubs because it can cause damage through root uptake.  Now that Bermuda is dormant it is also safe to use Atrazine on it. 

All of these are pre-emergence herbicides except Atrazine, a post-emergence herbicide. The most common post-emergence lawn herbicides are 2- and 3-way mixtures of broadleaf weed killers.  These do particularly good against most species of broadleaf weeds especially if the weeds are small.  The only drawback is that they have no residual activity, and once more weeds emerge you will need to retreat. If you have any questions, you can contact our office (478)- 862-5496 or (478)-825-6466 or contact your County Agent to determine which herbicides are best for your situation.

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