But let’s back up for just a moment to talk about the best way to keep weeds from ever coming up – having a thick, healthy lawn!
Weeds don’t overtake a nice lawn. Many people only think of using herbicides for weed control, but we need to take a look at the total management of a lawn. Herbicides should only be the last line of defense.
When properly managed, the turf grasses we grow in the Augusta area are highly competitive with weeds.
Obviously, weeds are unwelcome visitors in home lawns. Because of differences in color, leaf size, shape and growth habit, weeds detract from the natural beauty of a desirable turfgrass.
Weeds also compete with turfgrasses for sunlight, soil moisture and plant nutrients. Certain weed species, such as crabgrass, can become the dominant species in a lawn unless proper control practices are started and continued regularly.
Proper turf management is the key and the first step in preventing weeds from taking over the lawn.
Weeds don’t easily invade turf grasses that are properly fertilized, watered and mowed at the correct height and frequency. Weeds appear primarily in lawns that have bare or thin areas of turf.
These turf-management practices will help to prevent weed infestations in home lawns:
Select and establish a turfgrass adapted to the site. For example, tall fescue is an excellent permanent turf grass in north Georgia, but a poor choice for the Augusta area because of its inability to survive the hot summer. Bermuda makes a fine lawn, but it needs lots of sun (with the exception of Celebration and TifGrand cultivars). If your yard is shady, it will not grow well.
Apply the proper amount of fertilizer and lime at the correct times of the year.
Centipede requires only 1 pound of nitrogen per 1,000 square feet per year while hybrid Bermuda requires 4 to 6 pounds of nitrogen per 1,000 square feet per year. Overfertilizing centipede will promote decline and lead to increase problems with weeds.
The different turf grasses vary dramatically in their fertility needs. Soil testing through a County Extension office is the best way to determine the exact amounts of fertilizer and lime that is needed. When you get the results, pay special attention to the pH and potassium levels in the soil. Both are extremely important in growing a quality lawn.
Water properly and only when needed. Frequent, shallow watering will help weed seeds germinate and grow. This continues to be one of the biggest mistakes I see in home landscapes.
Most turf grasses in Augusta, on the average, need 1 inch of rainfall or irrigation per five to seven days during the growing season. Vary your watering based on the soil type and species of grass. Irrigate only when you don’t get that much rain. Don’t set your irrigation system and forget it. Infrequent irrigation that wets the soil from 6 to 8 inches deep will encourage turf grasses to grow deep roots and compete well with weeds.
Mow turf grass at the correct mowing height and frequency. Because they need to be fertilized differently, the various turf grasses need to be mowed at different heights, too.
The recommended mowing height for St. Augustine is 2 to 3 inches, while hybrid Bermuda is 0.5 to 1.5 inches. Generally, mow any turfgrass often enough so that only 1/4 to 1/3 of the leaf area is removed at any one time. Removing too much leaf or mowing below the recommended mowing height will stress the turf grass and make it less able to compete with weeds.
Remedial actions may be necessary to control diseases or insects. Both of these pests can decrease the stand of the turf grass, which will eventually favor the growth of weeds. For example, if you let chinch bugs kill St. Augustine, you can bet it will be overrun with weeds in that area. Fortunately, the proper turf grass management practices that limit weed encroachment will also limit disease and insect problems.
Use herbicides to control weeds only after following proper turf grass management practices. Using herbicides, without the corresponding use of proper management practices, won’t help develop a high quality, weed free lawn. If your grass is stressed and not healthy from something I have mentioned, herbicide labels will instruct you not to use them.
Herbicides should only be used to supplement weed control you achieve through proper turf grass management.
A variety of weeds can be a problem in home lawns. However, proper turf grass management, the first line of defense against weeds, can control many of these to an acceptable level.
Reach Sid Mullis, the director of the University of Georgia Extension Service office for Richmond County, at (706) 821-2349 or firstname.lastname@example.org.