The biggest issues in South Florida lawn care are excessive heat and lack of water. These problems are compounded by watering restrictions in most areas. Know the laws governing water use and make a plan to work within them to develop deep roots and a heat-tolerant lawn. Give the lawn year-round care for a green lawn that will withstand the worst of South Florida weather.
Plant a Heat Tolerant Grass
Choose a grass that will stand up to the heat of South Florida summers. Warm-season grasses such as St. Augustine grass, Zoysia grass, Bahia grass and Bermuda grass are heat tolerant and best suited for South Florida heat.
Water is a big issue in South Florida lawn care. Grass needs more frequent watering during hot, dry weather and watering restrictions in most areas compound the problem. The best strategy is to water only when necessary, but this may not be possible due to assigned watering days. Watering deeply and less frequently encourages the roots to grow deeper and helps the plant tolerate drought.
Water in the morning when the plants are actively taking in water. In the heat of the day, more water is lost to evaporation. At night, water stays on the foliage longer and may encourage fungal diseases. Give the lawn approximately 3/4 inch of water in the morning one day a week. Increase watering to two days per week during the hottest parts of the summer. A good indicator is to look for your footprints when you walk across the lawn. If your footprints are visible, the lawn needs water.
Apply High-Nitrogen Fertilizer
Use a high nitrogen fertilizer such as 15-0-15 or 15-2-15 on the lawn during the spring through fall; withhold fertilizer during periods of drought. Broadcast fertilizer on dry grass and water immediately. Fertilizers with some or all of the nitrogen available in a time-release form are best. Supplement the lawn with an iron spray if the soil pH is greater than 7.0. Yellow grass is a sign of iron deficiency in acid soils.
South Florida lawns need mowing year-round. During the summer, when the lawn is growing fast, mowing once or twice a week is required. In the winter months, mowing every few weeks will suffice. Never remove more than 1/3 of the blade in a single mowing. Mow long grass tall, then mow shorter a few days later. This is healthier for the grass than trimming away too much in a single mowing.
Use a pre-emergent herbicides that is labeled for the specific grass variety to prevent weeds. In south Florida, apply pre-emergent herbicides on or around February 1. Use post-emergent herbicides throughout the summer, whenever the temperature is below 85 degrees F and the grass has been receiving plenty of moisture.
Control Chinch Bugs
Chinch bugs are a major source of damage to South Florida lawns, causing yellowing, browning and eventually dead spots in the grass. Check for chinch bugs by cutting both ends off of a metal coffee can and pushing it halfway into the ground at the edge of a suspected area. Fill with water and wait five minutes. The beetle-like chinch bugs will float up to the surface of the water. Control chinch bugs with repeated applications of insecticide.
Dethatch when Needed
A thin layer of thatch insulates the lawn, protecting the roots from high heat, and aids in water retention. When the buildup becomes too thick, more than 1/2 inch, it becomes unhealthy for the lawn. Roots will grow in the thatch and not reach into the soil below, limiting the grass' ability to take in enough water and its resistance to drought.
Check for excessive thatch buildup every fall. For small thatch buildups, rake the lawn with a gardening rake or thatching rake. Use a mechanical dethatcher when the thatch buildup is more than one inch. Dethatch during warm, but not hot weather, in the early spring or fall. Aerate the lawn every two or three years.