How to Prepare Your St. Pete Lawn for Florida's Rainy Season

Florida's rainy season typically begins in early June and runs through late September. During this period, Tampa Bay receives the majority of its annual rainfall — often in intense afternoon storms. Your lawn needs to be in the right condition heading into this period to handle the volume of water without developing disease, weeds, or compaction problems.

Fertilize Before June 1 — Then Stop

Pinellas County has a nitrogen fertilizer blackout period from June 1 to September 30. You cannot legally apply nitrogen or phosphorus fertilizers during the rainy season — heavy rain washes them directly into Tampa Bay, causing algae blooms. Apply a slow-release nitrogen fertilizer in late April or May to feed the lawn heading into the rainy season.

Cut Your Irrigation Way Back

The single most common rainy-season mistake: running irrigation on the same schedule as spring. In June, July, and August, Tampa Bay typically gets more than enough rain to meet your lawn's water needs without any supplemental irrigation.

Install a rain sensor if you do not have one — it is legally required in Florida for new systems and shuts off irrigation automatically after rainfall. Overwatering in the rainy season creates ideal conditions for dollar weed, fungal diseases, and soggy spots where grass drowns.

Mow Weekly — Without Exception

Rainy season is when St. Augustine grass grows fastest — up to 2–3 inches per week in good conditions. If you fall behind on mowing, you will end up cutting more than 1/3 of the blade height at once, which stresses the lawn and leaves it vulnerable. Weekly mowing during rainy season is what keeps the lawn healthy — bi-weekly will result in shaggy, stressed grass that is harder to recover in fall.

Watch for Fungal Disease

The warm, wet rainy season is prime time for fungal diseases on St. Augustine lawns:

• Gray leaf spot: Small brown spots with gray centers on grass blades. Spreads rapidly in wet, hot conditions.
• Take-all root rot: Yellow patches that expand slowly; roots turn brown and rot. Caused by wet, stressed conditions. Prevention (proper watering) is the best approach.

Pre-Treat for Pests in Spring

Chinch bug pressure peaks during hot periods leading into and following rainy season. If you have had chinch bug problems before, talk to a pest control professional about preventive applications in May.