The types of disease that we see most often are:
Brown Patch is the most common disease of St. Augustine grass. It can occur in the late spring; however, it is usually the most active in the fall when conditions are the most favorable. Ideal conditions are cloudy days, excess moisture, 65 – 70 degree nighttime temperatures and daytime temperatures in the mid 70’s to mid 80’s and with excess nitrogen available. Typical symptoms are circular areas with brown centers with a yellow to light green area outlining the brown area. The fungus is active in the yellow to green area. Prevention of Brown Patch is difficult. Some suggestions are: do not use urea or nitrate based nitrogen fertilizers in the late summer or fall, also make sure your lawn drains and there are not any areas where excess moisture stands.
Apply Microlife Brown Patch 5-1-3 at a rate of 20 lbs. per 1000 Square Feet. When using as a preventative apply 30 days prior. The Microlife Brown Patch has Microbial Bacteria that eat the Fungi. Cool Huh? No Chemicals
Treatment should begin at the first sign on yellowing rings in the lawn. Fungicides are available such as Ortho Fungicide for Brown Patch or other equivalent products. Depending on which fungicide is used, treatments are made every 14 days to as much as every 30 days. Treatment must continue as long as conditions are right for brown patch to occur.
TAKE ALL PATCH
Take All Patch was identified some years back and looks similar to Brown Patch, except it occurs when the temperature is too high for Brown Patch to be active in the summer and too cold for it to occur in the spring. Take All Patch is a soil borne disease. Unlike Brown Patch, this disease can kill the St. Augustine if it is not treated. Multiple treatments of fungicide are usually needed and may not be effective at all.
If it is diagnosed in your lawn, it can be treated with fungicides that are not readily available at Home Depot or Lowe’s. Some of these Fungicides are no longer available to the public. We have only seen a few cases of Take All Patch in the past 10 years.
GREY LEAF SPOT
Gray Leaf Spot or Leaf Spot affects mainly St. Augustine grasses from springtime to fall. It appears as elongated circular spots on the grass blades with a brown or straw colored center, and black to purplish borders; and occurs during wet, humid weather. You will probably find this disease first appearing in shady areas of the lawn.