Home Gardening

Weed control starts with a healthy turf
The Coast Gardener Newspaper and Web Column - September 1, 2001

What exactly is a weed? Most people consider a weed a troublesome plant that is hard to control. However, a weed is any plant out of place. If you have zinnias growing in your vegetable garden, they can be called weeds if you don't want them growing there.

Lately, many homeowners have become quite frustrated with lawn weeds. There is a systematic approach to the madness. Let's take a look at the best approach for weed control in your lawn.

Weeds occur in home lawns during winter, spring, summer and fall. There are many different types of weeds that invade lawns. Broadleaf weeds, sedges and grasses all give homeowners headaches. Our climate is conducive to many types of weeds. They grow great here!

A thick, dense turfgrass canopy is the best defense one can have against invasive weeds. Diseases, insects, cold damage, inadequate sunlight, acid soils, poor drainage, fertilizer burn, poor fertility, poorly adapted turf type, poor mowing practices, or other factors can cause the turfgrass canopy to thin. These thin spots in your lawn are prime areas for weeds to pop up. Following recommended turf maintenance practices is the first level of defense against weed invasions. Herbicides can then be used to control weeds that still find their way to frustrate gardeners.

Summer annual weeds are at their peak. Several generations of weeds can be produced now until frost. Unfortunately, some annual summer weeds will leave scattered seeds on the ground throughout the winter just in time to germinate next spring.

Grassy summer annuals include crabgrass, goosegrass, bahiagrass, crowfootgrass, signalgrass, barnyardgrass and foxtail. Broadleaf annual weeds include ragweed, spurge, pigweed, chickweed, Florida betony, chamberbitter, Virginia buttonweed and dayflower. Purple and yellow nutsedge certainly cause big problems at times.

The first step in controlling weeds is to correctly identify the problem. Weeds have different treatment methods. What works on one weed may or may not work on another.

Preemergence herbicides are used to kill weed seeds before they germinate. Proper timing of these products is essential for effective control. A late summer application will kill winter weeds. Pay careful attention to temperature restrictions of preemergence herbicides. They will harm you grass if the temperature is too hot! In addition, make sure your grass is tolerant to the chosen product. St. Augustine and centipede are sensitive to some products. Read the label carefully.

Postemergence herbicides are used to kill existing weeds. Again, it is important to know what weed you are trying to kill. You will waste money, time and effort if you treat with the wrong product.

Following are a few pointers to keep your lawn healthy for the remainder of the summer:

Visit our Web site at www.MSUcares.com/crops/weeds/ for more weed control information including pictures of common lawn weeds. For complete lawn care information, print publication 1322 "Establish and Manage Your Home Lawn," or visit your local Extension office and request a copy.

These archived gardening columns were written by Chance McDavid, former Harrison County Extension Agent.