About this time each year, lawns that have been lush, thick and green throughout the early and midsummer months begin to look ragged, thin, and yellow.

Since most Kingsville area yards receive an application of fertilizer in the spring, there is often concern that insect pest or fungal disease are to blame for the poor appearance.

Take-all root rot or chinch bugs may very well be the problem and can be easily diagnosed allowing control measures to be implemented.

However, considering the length of our growing season in South Texas, the ragged appearance can often be the result of poor soil fertility.

The majority of Texas lawns need a low rate of nitrogen applied once in the spring and, if needed, once again in the fall no later than 6 weeks before the expected first frost.

A spring and fall fertilization strategy may work well in Central and North Texas, unfortunately, South Texas landscapes require additional applications if a lush green appearance is to be maintained.

The average growing season in the deep South Texas area is about 10 months.

As would be expected longer growing seasons require more nitrogen fertilizer to sustain lawn quality.

AgriLife Extension Turfgrass Specialist recommend that St. Augustinegrass in full sun receive 3 to 4 pounds of nitrogen per 1,000 square feet per year for a thick, green, lush turf.

In addition to a spring and fall application, 2 to 3 supplemental summer applications may be needed to enhance lawn quality in the Kingsville area.

Slow-release nitrogen sources are particularly suited for summer fertilization application.

With the temperature hitting the century mark daily, fertilizer burn or “foliar burn” becomes a major concern when discussing summer applications. Burn occurs on grass blades as a result of contact with soluble fertilizer.

The fertilizer salts draw moisture out of leaves and roots, leaving behind a browned-off appearance.

In order to avoid burn, apply fertilizer at the recommended rate (preferably utilizing soil test results) when the lawn is dry.

It is also good practice to water-in fertilizer with a normal irrigation cycle soon after the application.

High pH soils will also benefit from applications of iron sulfate or iron chelate to prevent iron chlorosis.

To learn more about fertilizing Texas Lawns, check the Extension Publication E-437 Lawn Fertilization for Texas Warm Season Grasses available the Texas AgriLife Extension and Research Turfgrass Web site: http://aggieturf.tamu.edu.