TAKE-ALL LAWN DISEASE

Lawn diseases are common in east Texas with the extremes of rainfall, so watch your grass closely this season for potential problems. Though simple tests can identify a white grub or chinch bug infestation, fungal diseases are more difficult to diagnose. An example is Take-all Root Rot, a relatively new disease which can attack both St. Augustinegrass and Bermudagrass.

Take-all patch is characterized by large areas of dead turf in either circular or irregular patterns. These dead areas can range in size from one foot to several yards in diameter. These may first occur on slopes or other areas which didn’t get as much water and therefore suffer more stress during drought. This disease can easily be mistaken for brown patch or grub damage, but a distinguishing characteristic is extensive root rotting.

Stolons will have lesions or show a brownish discoloration. The fungus is most active during early spring and fall when there is plenty of moisture, and nighttime temperatures drop below 70 degrees. Though the best time to chemically treat this disease in the fall, there are measures which can be taken at any time. Thatch, for example, provides an environment which encourages fungal growth and should be removed. Aerating the soil may also be of benefit. And recent studies have shown that broadcasting a 1/4″ layer of finely ground peat moss over the area provides control.

This disease is difficult to diagnose and control. It also has the potential to live up to its name and “take all” of a lawn. If you suspect a fungal problem, call the Smith County Extension Office for information on sending a sample to the Texas A&M Plant Disease Diagnosis Lab.

Geneva Thomas, former Smith County Master Gardener
Texas A&M AgriLife Extension Service


TAKE-ALL ROOT ROT

The yellowing of leaves and the decay of grass roots is the first symptom of Take-All Root Rot followed by the turf thinning in irregular shapes. The roots can become so rotted that grass can easily be pulled up. Take-All Root Rot spreads mainly from fall through spring when there is abundant moisture and cool, mild temperatures. The dieback symptoms appear in the hot stressful days of summer. Take-All Root Rot attacks St. Augustine, Zoysia and Bermuda and could eventually kill the entire lawn.

Do you have good drainage in your yard? Water standing for long periods can cause problems. Level low areas, and aerate your yards with heavy clay soil at least once a year to improve drainage and reduce soil compaction. If water flowing from drains is the problem, consider French drains or a dry creek bed.

Avoid heavy fertilization of the turf area as excessive nitrogen seems to promote Take-All Root Rot.

Raise mowing height to reduce stress and avoid broadleaf herbicides.

Betty Hicks, former Smith County Master Gardener
Texas A&M AgriLife Extension Service

Posted in Turf Pests and Problems