Does your lawn have brown spots?
As temperatures turn cooler, the stress from earlier in the year starts to show. Fungus like to starts growing as temperatures cool down. While not all fungi in our soil are bad there are a few that do cause issues with our plants, trees, and turf. St. Augustine is more sensitive to harmful fungi than most other grasses.
The most common forms of fungi are known as take-all root rot (Gaeumannomyces graminis var. graminis) or large patch (Rhizoctonia solani) fungus. Both forms of fungus are bad and need to be treated aggressively and quickly.
Another form of fungus is known as fairy ring. fairy ring causes brown or dark green circles that appear on your lawn. This form is more commonly associated in areas where a tree has been cut down or some other type of decaying plant tissue. There are 3 different types that can cause this fairy ring.
It is important to understand that you can not kill the fungus but only suppress and control the issue.