Lawns

To have a desirable lawn for all seasons in North Texas, gardeners must choose the right type of grass for the location. In addition, soil must be prepared, and the lawn needs mowing, water, and fertilizer. There may be problem areas related to weeds, insects, and diseases. The problem areas will need to be identified and treated. If you are not familiar with your soil, you may benefit from a soil test. The following link will give you information about how and where to send a soil sample.  Soil testing submittal form.

The Aggie Turf site contains tremendous information related to Texas lawns.

North Texas warm-season lawns

Bermudagrass is the most widely used turfgrass in Texas. It originated in Africa. It tolerates very little shade, grows in the spring after temperatures reach 60 degrees, and turns brown in a cool fall. It spreads aggressively both by rhizomes and stolons creating a constant need for trimming. Bermudagrass is grown easily from seeds. Many varieties are available in addition to common bermudagrass.

St. Augustinegrass is primarily of tropical origin. It grows well in most warm and humid areas, and it is usually tolerant to shade, but intolerant to heavy traffic. St. Augustine is best planted in sod. It spreads quickly by stolons. St. Augustinegrass needs more water, is less cold tolerant, and is more susceptible to iron chlorosis than bermudagrass. Because of its inability to tolerate extreme cold, it is frequently stressed in North Texas. This means it is prone to diseases and pests. There are several varieties of St. Augustine. ’Common’ St. Augustinegrass is widely used in the North Texas area. To determine the best choice of the varieties of St. Augustine compare their tolerance of cold, heat, drought, and shade. Also compare resistance to common pests such as St. Augustine Decline (SAD), chinch bug, brown patch, and take-all root rot.

Buffalograss is native to the American plains from Texas to Canada in areas with annual precipitation of 25” or less. It tolerates infrequent mowing, and it tolerates drought very well. It has poor shade tolerance. It grows best in well-drained, clay soil with slightly alkaline soil pH.

Centipedegrass does best in sandy, well-drained soil. It does poorly in alkaline soil. It tolerates infrequent mowing, requires less nitrogen than bermudagrass or St Augustine, and has some shade tolerance. It is available in seeds or sod.

Zoysiagrass is native to Asia. It tolerates low temperatures better than bermudagrass. It spreads by rhizomes and stolons, has a rather slow growth rate, but forms a strong, dense turf. It requires a longer grow-in period for sod or plugs.

Lawn establishment

The preparation of the soil under the new lawn is the same regardless of the establishment method – whether by seed, sod, or sprigs:

  • Select the proper type of grass and the proper variety.
  • Decide when to plant, allowing enough time to complete the steps below.
  • Have the soil tested.
  • Control perennial grasses and broadleaf weeds.
  • Grade and till the soil.
  • Apply soil modification if needed.
  • Apply the final soil preparations before planting.
  • Plant the seed, sod, sprigs, and/or plugs.

It may be necessary to alter the character of the soil to obtain best results for the new lawn. The best soil for turf is a sandy loam soil high in organic matter. If the original surface soil is heavy clay, organic matter may be thoroughly mixed into the top 4” to 6” of the seedbed by repeated cultivation operations such as roto-tilling. Location of underground utility lines should be considered prior to cultivation. The lawn area should be graded so that the lawn slopes away from all buildings. The soil should be firmed with a walk-behind roller. The lawn should have no low areas which may trap water. After working the soil, irrigate it to promote settling before planting.

Seeds are generally the least expensive way to establish turf.   The best temperature range for seed germination of warm-season grasses is from 70 to 90 degrees F.   Late spring to early summer is probably the best time to seed bermudagrass and other warm season turfgrasses.

Sodding is the quickest way to establish a lawn, and it provides immediate soil erosion control. It can be used to reroot lawns. It eliminates the need for weed control during establishment, and can be planted nearly year-round although the best time is when the turf grass is actively growing. It can be used for total lawn installation or repair of smaller areas. To sod a prepared lawn, topdress it with a sandy loam topsoil that is free of debris. The surface should be smooth and firm. Lay the sod blocks or rolls in the same manner that bricks are placed. Butt each sod piece against the others as tightly as possible. Roll it lightly. Keep the soil moist until it is well rooted. However, do not overwater.

Lawns can also be established or repaired using plugs during the growing season. The plugs should be firmly pressed into the soil and rolled to give a smooth surface for mowing.

Mowing

A lawn should be cut to the appropriate cutting height and at the proper frequency. Good mowing practices can reduce the stress on the lawn. The leaves of the grasses have important functions to perform in obtaining and storing nutrients for the plants. The leaves help to insulate the base and roots of the plant from temperature extremes. Grass plants have a “growing point” where all of the leaves originate. The growing point stays near the soil surface when grass is mowed frequently. When people let their lawns get really “hairy,” the growing point begins to elevate from the soil surface. When finally mowed, the growing point may be cut and removed with the rest of the clippings. This means death to the plant. Frequent mowing, never removing more than 1/3 of the grass blade ensures that the growing point will stay near the soil surface and the turf will stay healthy and dense. When care is taken not to mow the lawn too closely, the grass will develop a deeper and better root system, and the grass will be less prone to disease and temperature stress.

Irrigation

Deep watering encourages the development of an extensive root system. A well-developed root system can use the nutrients and water in the soil more efficiently than a shallow root system.

Light, frequent sprinklings produce shallow, weak root systems, which encourage weed invasion. Shallow rooting inhibits plants from using food or soil efficiently.

In winter, water the lawn only as needed during excessively dry periods. Just as lack of water harms plants, so does too much water. When water is applied too often, the soil becomes saturated forcing out air. This deprives the root system of the oxygen to grow and take in water resulting in significant stress to the plant.

Irrigation needs vary with methods of lawn establishment. Newly seeded areas should be watered lightly, but effectively, at frequent intervals. During this initial growth period of 10 days to 2 weeks, keep the seeds moist but not saturated. This may mean several times daily during hot and/or windy weather. If young plants are allowed to dry out, they may die. Slowly reduce the watering frequency for about 1 month after seeding. Then water on an as needed basis. When water is needed, water to a depth of 6″ (about one inch of water). The AgriLife Aggie Turf site or Earth-Kind Irrigation Audit article will help you figure out how long it will take your irrigation system to deliver 1″ of water.   Newly sodded areas should be watered much like established turf except more frequently. The newly sodded area should be soaked with enough water to ensure that the soil under it is wet to a depth of 2-3 inches. Each time the sod begins to dry out, soak it again. After 2 weeks, roots are developing, and the sod can be watered on an as-needed basis.

The best time to water is early morning. Less water is lost to evaporation. Late evening watering can keep the grass moist all night increasing risk for disease, particularly fungal diseases.

Fertility Program

Applying fertilizer to lawns can help keep the grass healthy and the yard looking green. Yet these nutrients must be managed to preserve plant health and to reduce any potential pollution to our waterways through fertilizer runoff. For more information on fertilizing lawns, see publication Lawn Fertilization for Texas Warm-Season Grasses, available from the Texas Agrilife Extension Bookstore.

Turfgrass pest management

Turf pest issues include weeds, insects, and diseases.

Weeds can create an unsightly appearance in lawns. A dense, healthy stand of turf provides the best defense against lawn weeds, and a dense, healthy turf is best achieved via proper watering, fertilization, and mowing. Many weeds can be controlled with preemergence herbicides applied in early spring. Dallisgrass is best controlled by spot-treating the weedy plants with an appropriate post emergence herbicide. On St Augustine lawns, use only materials recommended for St. Augustinegrass because the grass may be damaged by some materials that are safe for bermudagrass. With its rapid growth, nutsedge can be a problem. St. Augustingrass effectively competes with nutsedge and crowds it out; however, when St. Augustine is damaged by insects or disease, there may be a problem with nutsedge. For more information, visit the weed page on the Aggie Turf site. Remember to follow label recommendations for all herbicides, and use them only on the grasses specified on the label.

The major insects affecting lawns in Texas are chinch bugs, grubs, and lawn caterpillars. Chinch bug damage appears as irregular patches in open, sunny areas of the lawn, often beside the sidewalk or driveway. The grass turns yellow and, if untreated, eventually turns brown and dies. Chinch bug treatment

White grubs, the larvae of the May or June beetles, feed on the roots of lawns 1-2 inches below the surface. If the infestation is heavy, the grubs will consume the entire root system. Treatment is not necessary unless there are more than 5 or 6 grubs per square foot. It is critical to treat the developing larva at the proper stage of growth.  For more information, go to Grub treatment

Lawn caterpillars have an adult moth stage that lays eggs in the turf. These eggs develop into the caterpillars, which is the stage that damage the turf.  Armyworm information and treatment.

The goal of pest management should be to control pest populations to levels that do not cause significant damage. It does not forever eliminate or eradicate the pests.

Even properly managed lawns may be attacked by diseases, but they recover much faster that those lawns that are poorly managed. Brown patch is a fungus disease that damages St. Augustinegrass in spring and early fall. It is characterized by circular patches of yellow or brown grass that can vary from less than 1 foot to several feet in diameter. The fungus is most active when humidity is high and the air temperature is between 75 and 85 degrees F. To treat the brown patch, apply preventive fungicides in early fall. Take-all root rot is a serious fungus disease of St. Augustinegrass and can cause problems on bermudagrass also. It is active when moisture is abundant and temperatures are moderate. The first symptom is usually a yellowing of the grass leaves. Unlike the symptoms of brown patch, the leaves of take-all infected plants do not easily separate from the plant when pulled. Much is left to be learned about this disease. Good drainage to the turf and control of thatch build-up appear to be helpful. St. Augustine decline (SAD), a viral disease, causes chlorotic (abnormally yellow) mottling of the leaf blade and a general decline in lawn vigor. Since the disease is a virus, there are no chemical control methods. Some improved varieties of St. Augustinegrasses are resistant to SAD and may be plugged into an infected lawn and the new variety will eventually replace the weakened turf. Leaf spot diseases cause considerable damage to St. Augustine and bermudagrass lawns.   For more information, go to the aggieturf website referenced at the top of this article.

More information may be obtained from above mentioned websites and/or the Denton County Master Gardener Help Desk (master.gardener@dentoncounty.com). Remember to follow label recommendations for all fungicides, and use them only on the grasses specified on the label.

Comments are closed.