Keith Hansen

The big three turf grasses that make up most East Texas lawns are St. Augustine, Bermuda and centipede. The least familiar of these grasses to most folks is centipede.

Centipede is a grass native to China and Southeast Asia, originally brought over from South China as seed by the plant explorer Frank Myers during a collecting expedition in 1916.

Its name supposedly comes from its creeping growth habit with short upright stems that resemble a centipede. Perhaps my imagination is not so vivid, but I just cannot see a centipede when I look at the runners.

Centipede grass is very well-adapted to the sandy, acidic soils of southeastern United States where annual rainfall is more than 40 inches. Centipede is moderately shade tolerant, being in between St. Augustine and Bermuda. However, like all three grasses, it grows best in full sun. It forms a dense turf and has a relatively slow rate of growth.

Centipede has a natural light green color and is more suited to acid soils (pH 5.0 to 6.0) than most turf grasses. However, according to the University of Georgia, recent research suggests that centipede actually grows better when the soil pH is 6.0 to 6.5. High rates of fertilizer (especially nitrogen) produce an unnatural dark green color and often result in yellowing, reduced cold and drought tolerance, thatch accumulation and turf loss.

Cold temperatures limit its northern hardiness, being slightly more cold tolerant than St. Augustine. In mild climates, centipede remains green all year long, but leaves and young stolons are killed during hard freezes. It does not have a true dormant state in the winter and resumes growth whenever temperatures are favorable. Intermittent cold and warm periods during late winter and early spring can cause severe injury. If the warm/cold cycle happens several times during a winter, the grass is depleted of energy reserves and is susceptible to winterkill.

Often in spring, centipede lawns can develop yellow patches which are usually brought on by cool soils and a weakened root system. Once the weather stays consistently warm, the grass usually grows out of the condition.

Centipede can be established from sod, sprigs or seed. Successful lawn establishment by seed is very dependent on a good seedbed preparation. You can’t just throw seed on the ground and expect a wonderful lawn. The soil should be disked or rototilled, pulverized and firmed with a roller. Seed should be broadcast with a seeder or by hand. To aid uniform distribution, mix one-third to one-half pound of seed with about a gallon of fine sand and evenly distribute across 1,000 square feet.

After planting, the site should be firmed with a roller and watered slightly. The seedbed should be kept moist, but not wet, for 14 to 21 days after planting. If the area is too large to keep watered, the site should not be planted until soil moisture is adequate. A complete fertilizer should be applied at the time of planting at a rate of one pound of nitrogen per 1,000 square feet.

Too often, homeowners try to push centipede grass with nitrogen to enhance color and growth. While this may work in the short run, it can lead to serious problems later on.

How much you fertilize a centipede lawn depends on what kind of soil you have, and preferably should be based on soil test results. Centipede fertilization rates should not exceed one pound of nitrogen per 1,000 square feet per year on clay soils applied, or two pounds of nitrogen per 1,000 square feet per year on sandy soils.

The first fertilizer application of the year should be made in mid-May at a rate of one pound of nitrogen per 1,000 square feet, and again in September with one half to one pound of nitrogen. Centipede should not be pushed into spring growth by early applications of fertilizer.

Avoid using fertilizers with high levels of phosphorus (the middle number) since phosphorus contributes to iron deficiency (yellow patches) in centipede. On sandy soils and soils low in potassium, spring and fall applications of potassium help promote root development and reduce winter kill.

Also, since centipede prefers more acidic soils, do not lime centipede lawns, unless the pH falls below 5.3, and then lime only lightly. For best fertilizer results, get your soil tested.

Centipede is naturally shallow rooted and water management is critical during the summer. Dr. Richard Duble, a turfgrass professor at Texas A&M University, says that centipede grass is not as drought tolerant as some people have been led to believe, and improper watering during drought stress can cause problems.

Duble suggests to water when centipede just begins to show signs of water stress – a wilted and discolored appearance. Light, frequent applications of water should be avoided since it promotes shallow rooting. Thoroughly wet the soil 4 to 6 inches deep when the grass begins to show signs of stress. Sandy soils require more frequent applications of water, but the soil should be wet 6 to 8 inches deep after each irrigation. Centipede should also be watered during dry winters to avoid desiccation.

Although centipede may not need to be mowed quite as often as St. Augustine or Bermuda, it still needs regular mowing to maintain a quality turf. Ideal mowing height is between one inch for sun and two inches in the shade, no higher. Remove no more than one-third of the leaf blade per mowing. Mowing less frequently, or at a taller height can lead to thatch and serious decline problems after a few years.

Excessive nitrogen fertilization, improper watering and mowing, and excessive use of pesticides account for many of the problems homeowners sometimes have with centipede lawns.

Keith Hansen is Smith County Horticulturist with Texas AgriLife Extension Service. His web page is http://EastTexasGardening.tamu.edu His blog is http://agrilifeblogs.tamu.edu/mt/etg Texas AgriLife Extension Service educational programs are open to all individuals without regard to race, color, sex, disability, religion, age or national origin.

Keith Hansen
()