Summers in St. Louis can be harsh on lawns. Especially this summer. We went from rain almost every other day to hot humid weather and no rain at all. These past few weeks have brought almost no rain and hot days and warm nights. Now fungus and lawn disease is taking over. Brown patch is the most prevalent fungus in lawns right now. The lawn will start to brown and it will slowly spread. This might be confused with general lawn burnout. Typically when a lawn burns out it will turn grey first and then to brown.
The fungus is brought on by spores already existent in the lawn and they only become active under the right conditions. These past few weeks in St. Louis have provided prime conditions for brown patch in St. Louis lawns. The warm humid nights allow the brown patch to thrive. A fungicide can be applied to prevent the spread of lawn disease and when conditions are right the lawn will fill back in.
Correct watering can also prevent fungus and disease in your lawn. Lawns should be watered at the most two times per week during dry portions of the summer. If we receive regular rain here in St. Louis, then watering is not required. Set your watering system so your lawn gets watered deeply and infrequently. The best watering program will water your lawn once per week and apply one inch to one and a half inches of water. This will promote root growth deep into the soil. Watering every day or multiple times per day will promote shallow root growth and enhance the chance of disease in you lawn.
Allow you lawn to dry out between watering