Bermuda grass (Cynodon dactylon), widely grown for lawns and playing fields in Texas, is a warm-season grass, meaning that it turns green in spring and loses its green as it goes dormant in late autumn. It spreads by above-ground stems called stolons and underground stems called rhizomes.
Although a few cold-hardy Bermuda grass cultivars will grow in U.S. Department of Agriculture plant hardiness zones 5 and 6, the most important cultivars, including those widely grown for lawns and playing fields in Texas, grow in USDA zones 7 through 10.
Begin mowing Bermuda grass when it starts turning green in the spring. Mow common Bermuda grass 1 to 2 inches high and hybrid varieties 1/2 to 1 1/2 inches high. Do not mow more than one-third of the grass blades at any one time. You’ll need to mow more often at lower heights, but you’ll get better quality grass.
If your soil has not been tested for nutrient deficiencies, scatter 1 pound of water-soluble nitrogen over 1,000 square feet of Bermuda grass every four to six weeks beginning in the spring after the grass turns green and there is no danger of a late spring frost. Do not fertilize after September.
Fertilizer numbers show the ratio by weight of nitrogen, phosphorus and potassium in a bag of fertilizer. Use 15-5-10 or any fertilizer with a 3-1-2 ratio. To determine how much 15-5-10 soluble fertilizer is needed to supply 1 pound of nitrogen, divide 100 by the first number in the fertilizer. For example, 6.6 pounds of 15-5-10 will yield the 1 pound of soluble nitrogen you need to scatter over 1,000 square feet of grass; 100 divided by 15 equals 6.6.
If you want to use slow-release fertilizer instead of soluble fertilizer, add 1 1/2 pounds of nitrogen to 1,000 square feet every eight to 10 weeks. To determine how much 15-5-10 slow-release fertilizer you need to supply 1 1/2 pounds of nitrogen, divide 150 by 15. The answer: 10 pounds.
Always water well after applying fertilizer.
To maintain healthy Bermuda grass during the spring and summer, wet the soil 6 inches deep, but only when it shows signs of stress. It needs water if your footprints linger, if its leaves fold or it turns a dull bluish-green. You should be able to push a spade easily into moist soil.
To find how much water your sprinklers deliver, place five or six open cat food or tuna fish cans randomly around your lawn. Sprinkle for 30 minutes. Measure the depth of water in each can with a ruler. Add the amounts together, and divide the total amount of water collected by the number of cans.
Use a spade to find the depth of soil moisture after the 30 minutes. For example, if you calculated that your sprinkler sprayed 1/2 inch of water in 30 minutes, wetting the soil 3 inches deep, you will need to spray for an hour to wet it 6 inches deep. Do not apply water faster than the soil can absorb it.
In fall and winter, water periodically during windy, dry, warm weather.
Excessive watering and fertilizing causes thatch, a layer of un-decomposed plant matter that builds at the base of the grass. Use a knife or spade to remove a small patch of grass so you can measure the thatch. A thatch layer from 1/4 to 1/2 inch thick acts as a mulch to hold in water, helps the grass withstand traffic and decreases soil compaction. Thatch more than 1/2 inch thick, prevents air and water from reaching the soil and encourages disease and insects.
If thatch builds to more than 1/2 inch thick at the grass roots, mow the lawn with a vertical mower in May. Many garden supply centers rent vertical mowers that pull plugs of soil from the ground, usually requiring several passes. An ideal vertical mower should remove eight or nine plugs per square foot, each 2 to 3 inches long and 1/2 to 3/4 inch wide.
To control small weeds, spray them with herbicide containing 2,4-D, dicamba or MCPP. The application rates of herbicides vary by brand and formulation. For example, you would mix 1/2 tablespoon of an herbicide containing 46.3 percent of the active ingredient 2,4-D to enough water to cover 1,000 square feet of lawn. An herbicide containing 26 percent of the active ingredient MCPP would require 1 1/2 fluid ounces in 2 1/2 gallons of water per 1,000 square feet of lawn. Other brands and active ingredients would have different application rates. Many brands post their product labels online telling you what sprayer nozzles and power to use and necessary precautions including time to wait before using the lawn after application. These chemicals are all toxic, so you need to wear coveralls, waterproof gloves and face shields.
White grubs, the larvae of nearly 100 species of beetles, may cause irregular patches of dead or dying Bermuda grass in Texas. The grubs typically feed in the top few inches of soil, doing the most damage to Bermuda grass when they are 1/2 to 1 inch long.
To find out if you need to treat your lawn for grubs, dig up several patches of soil 4 inches deep and 3 to 4 inches wide. If you find more than five larvae per square foot you may need to treat your lawn, but even more than five may not hurt your grass.
Many garden supply centers sell Steinerema and Heterohabditis, tiny nematodes or round worms that eat larvae and other insects in soil. This is the best way to treat Bermuda grass without resorting to toxic chemicals. You typically mix these with water and spray them on your lawn. Water your lawn with 1/4 inch of water before and after applying.