Preventing and Treating Brown Patches in St. Augustine Grass
Updated: Feb 24, 2020
What causes brown patches in St. Augustine grass?
Brown patches in your St. Augustine grass is a problem that effects the majority yards in Florida during the cooler months. These brown patches are caused by a fungus/mold called, unsurprisingly, Brown Patch Fungus. There are a few simple tips you can follow to help treat and prevent this fungus from taking over your beautiful lawn.
Tip 1: Don't water at the wrong time.
Do you water your lawn in the evening or early in the morning hours? This may be the cause of the brown patches in your yard. Watering too early can leave your lawn damp at night. Wet lawns and cool weather are the perfect conditions for this fungus to grow and thrive in. If you are watering at the wrong time, adjust your irrigation system to run in the morning preferably right before sunrise. This will allow the soil time to soak in the water and will give the grass blades time to dry in the Florida sunshine before nightfall.
Tip 2: Do not over water your lawn.
Brown patch fungus loves damp conditions so watering your yard too frequently will only encourage the fungus to grow and spread. St. Augustine grass is somewhat drought tolerant and does best when watering is done only as needed. The recommended depth to water is 4 to 6 inches. This does not mean 4 to 6 inches of water but instead means the depth into the ground which the water is reaching. Based on your soil, slope of your yard, etc. the amount of water needed will vary.
Tip 3: Avoid fertilizer high in nitrogen in early spring and late fall.
Fertilizer that is high in nitrogen promotes lush green growth. This can be an issue for you in the early spring and late fall though. Nitrogen also provides a nice platform for fungus to grow on in the cooler months. Fertilizing too early or late with the wrong fertilizer can lead to fungus growth. Fertilizer high in nitrogen should only be used in late spring or in the summer.