Hi edythaii!
Yellowing of your St. Augustine grass maybe because of lack of fertilizer or disease attacks. Generally, to get rid of these problems, follow the following suggestions...
Brown patch appears on the grass that has been fertilized more than its requirement. Brown patch can be prevented by watering your grass in the late evening when the temperature has lowered and the sun has gone down.
The best way to tell if your St. Augustine Grass has encountered a disease is to send a sample of the grass for testing, which can be costly. SAD and brown patch at times are not treatable, depending on how much the disease has affected the grass. If the disease is caught early enough, you can treat it with fertilizers.
Good sanitation, including mowing, watering and fertilizing, can prevent St. Augustine grass from contracting diseases. Mowing should be done frequently. St. Augustine grass thrives and lasts longer if kept at a 2 to 2-½ inch height. After mowing, be sure to leave the clippings to promote growth and protect the lawn from diseases. During warmer weather months, it is a good rule of thumb to be on the lookout for pests that may affect the growth of your grass. Some insects can kill the grass and cause diseases.
When fertilizing St. Augustine Grass, buy a fertilizer that is meant specifically for St. Augustine Grass and other grasses that survive in warmer climates. There are several grass fertilizers that are specific to colder temperature grass. Using a fertilizer that is used for grass in colder regions can result in killing the St. Augustine Grass or cause unnecessary diseases.
Happy gardening!
Cris
