Winter Care (September - February)
For the most part you will continue the same mowing routine you used from March - September until the grass goes dormant and does not require mowing. The general rule of thumb of cutting no more then 1/3 of the grass off per cut should still be followed and we recommend cutting the grass an inch higher so 3 - 3.5" instead of the 2.5-3" you would use during the spring and summer.
Continue the fertilizer schedule we recommend in the spring applying 1 - 1.5 lbs of nitrogen per 1,000 sq ft every 2 months. Without knowing the results from a soil test we recommend a fertilizer that is nitrogen only (21-0-0) or is low in phosphorus (21-3-6 or 15-0-15) to prevent yellowing caused by iron chlorosis we recommend applying liquid or granular iron fertilizer also. 4 - 6 weeks before the first expected freeze apply a low nitrogen, high potassium fertilizer (5-10-10) apply no more then a half pound of nitrogen per 1,000 sq ft. Do not fertilizer the lawns again until March.
Even though St. Augustine grass is dormant in the winter it is still a good idea to water is occasionally. If the weather gets warm or it doesn't rain for awhile and it gets dry or its been abnormally windy.
Apply preemergent herbicides for winter weeds when the soil temperature drops to 70 degrees. Then apply postemergent herbicides as needed.
St. Augustine grass lawns shouldn't have any detrimental insect activity during the winter.