St. Augustine grass is a popular grass choice in Texas and along the gulf coast area. Its dense, wide blades carpet the ground, providing a thick, beautiful lawn with proper watering and soil conditions. It grows well in a wide variety of soils and needs full sun to part shade to thrive. However, there are many possible problems with St. Augustine grass, including insects and disease, that should be considered.
Chinch bugs are small, slender bugs that can be a big problem in St. Augustine lawns. They cause irregularly shaped patches of dead or stunted grasses that can expand rapidly, especially in sunny areas during the hot, dry Texas summers. Preventing drought stress in your yard by keeping it well watered and encouraging beneficial insects and birds by avoiding the use of chemical treatments in the lawn can go a long way towards preventing chinch bugs.
Grubs are white, c-shaped pests that feed on the roots of St. Augustine and other grasses during summer and fall. They cause brown, damaged lawns that can be lifted in large pieces like carpet. Proper watering, mowing high and adding beneficial nematodes can help prevent a grub infestation in St. Augustine lawns.
Two common fungal diseases that affect St. Augustine lawns in Texas are Take-all Patch and Brown Patch. Characterized by yellow grass and dark, rotting roots that can be easily pulled out, Take-all Patch spreads from fall to spring in cool, moist conditions, but symptoms appear in the hot, dry summer months. Brown Patch leaves circular brown, dead patches of grass blades in the lawn and also spreads during the cooler months. Wet weather and over-watering contribute to the spread of Brown Patch. Both diseases are best controlled with proper irrigation, avoiding heavy fertilization and the use of fungicides when symptoms first appear.
St. Augustine grass is only drought-tolerant in shady areas. When St. Augustine lawns are in sunny areas with no shade, the leaf blades will begin to curl and lose their green color, turning silverish instead. In Texas, St. Augustine grass needs a lot of water to survive the hot, dry summers.
In soils that are alkaline or iron deficient, St. Augustine grass can develop iron chlorosis, in which the blades of grass become striped with yellow or turn completely yellow. To prevent iron chlorosis, avoid fertilizers that are high in phosphorus and apply iron supplements like iron sulfate and iron chelate to leaves of the grass.