Every lawn, whether new or established, is susceptible to a variety of lawn diseases. Most lawn disease starts with a fungus. Fungi are an oddity because they don’t set seeds; instead, they propagate by distributing spores in their surrounding area. Some of the spores are picked up by wind or animals and distributed in new locations.
One of the biggest problems in controlling lawn diseases is diagnosis. By the time signs of infection are evident, the fungus that causes it is often difficult to control. Although there are dozens of types of lawn disease, most can be prevented through regular lawn care. Most fungus spores lie dormant until conditions are right for them to grow and infect your lawn. Generally, fungus spores need warm temperatures, a moist environment, a source of nutrition and a susceptible host. Although you can’t control the weather, you can deprive them of the nutrients they need as well as a susceptible host.
Water your lawn deeply and infrequently to deprive fungus of the damp environment it needs. In addition to helping the prevention of lawn disease, deep and infrequent watering encourages your turf to sink deeper roots. Water only when the surface soil is dry to your touch and then water to a depth of two to three inches. You can gauge how much water your lawn is getting by “planting” a small container (such as a rain gauge or tuna can) in a corner of your yard. In addition, schedule irrigation in the morning to give excess water a chance to evaporate. Never water at night.
Heavy thatch layers (over ½ inch) hold both heat and moisture and provide fungus with a ready supply of nutrients. Thatch also impedes drainage and blocks the airflow your lawn needs to thrive. Annual core aeration in the spring is the best way to control thatch buildup. You can also control thatch during the growing season by maintaining your lawn at a 2 ½ to 3 inch height and cutting no more than ⅓ of the height when you mow.
Brownpatch is a fungus disease that damages St. Augustine in spring and early fall. Brownpatch is characterized by circular patches of yellow or brown grass that may vary from less than one foot to several feet of diameter. The outside of the circle has a “smoke ring” appearance caused by the actively spreading fungus. In this area, the leaves of the grass may be easily pulled from the stem because of the deterioration caused by the fungus. from the stem because of the deterioration caused by the fungus. The grass in the center of the circular patch may recover within weeks, giving the disease area a doughnut shaped appearance. The fungus is most active when humidity is high and the air temperature is between 75 and 85 degrees.
Leaf spots on turfgrass leaf blades begin as small red to purplish ovals that later develop tan centers of dead tissue with darker borders ("eye spots.") The fungi that cause leaf spots directly penetrate leaf sheaths and blades at random or enter via mowing wounds which commonly leads to a tip blight. When turfgrass is succulent from recent nitrogen fertilization and there is abundant moisture on the leaf blades, numerous leaf spot infections per blade can occur. The leaf spots may then coalesce and cause extensive blighting. The fungus may even invade the crowns and roots, leaving the plants weakened and rotted. This severe stage is called "melting-out." Large areas of dead or badly weakened turfgrass may result.
Take-all patch is a serious fungus disease of St. Augustine grass and can also cause problems on Bermuda grass. It seems to be active during the fall, winter and spring when there is abundant moisture and temperatures are moderate. The disease has the ability to destroy large sections of turfgrass if left uncontrolled, and has proven to be a difficult disease to control. When the disease is active, the first symptom is often a yellowing of the leaves, which may eventually die and turn brown. The area of discolored and dying leaves may be circular or irregular in shape and at least up to 20 feet in diameter. Unlike brown patch, the leaves of take-all infected plants do not easily separate from the plant when pulled. The roots are sometimes so rotted that damaged stolons are easily pulled from the ground.
Although slime molds do not cause disease, their sudden appearance as white, gray, purple, or brown patches on grasses may cause alarm. What is the good news? Slime mold will not harm your grass or ornamental plants. These organisms use the leaves and stems of grasses to support their reproductive structures and ultimately facilitate their dispersal to surrounding areas. They may therefore occur on any turf grass species. They may sometimes be confused with Powdery mildew or Stripe smut. Symptoms are large numbers of pinhead-sized fruiting bodies (sporangia) of these organisms may suddenly appear on grass blades and stems in circular to irregular patches 1-24 in. (2-60 cm) in diameter. The sporangia are typically white, gray, or purplish brown, but other colors are also possible. The affected patches of grass do not normally die or turn yellow, and the sporangia usually disappear within 1-2 weeks. These organisms may appear in the same location each year. Slime molds feed on bacteria. They are not parasitic on grasses, but they may shade individual grass leaves and interfere with photosynthesis. Thus, some yellowing of leaves is possible when slime mold reproduction is heavy, and weakened plants may become more susceptible to infection by pathogenic fungi.
At Texas Lawn Ranger Lawn & Landscaping, we will diagnose and treat the different types of turf-grass diseases. Whether it is the result of Brown Patch, Leaf Spot, Rust, or Take-all or other diseases we can help. This process involves a visit to your lawn to closely inspect symptoms and take a sample to test if necessary. Once the diagnosis is complete, a recommendation for treatment is made. Our trained professionals can then apply the selected treatment to leave you with a revitalized lawn.
Call Texas Lawn Ranger at 817-709-1695 to get started on a Disease Free yard today!!
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