Rainy Season: Signs Your Lawn is Getting too Much Water

Rainy season is here. That means it’s time to turn down your irrigation.

Rainy season in South Florida runs from May 15th to October 15th but it’s also the hottest time of the year. Our sandy soil combined with South Florida’s hot days of summer can mean your lawn needs more water than usual but watering your lawn too much will only cause other problems. Too much water interferes with healthy grass growth and makes the lawn susceptible to pests and diseases. So how do you know when you can skip a round of watering? Here are some signs you may be over watering your lawn.

Growing Like Weeds

If weeds are invading your lawn with alarming speed, that could be a sign of over watering. Weeds like sedge and crab grass thrive in a too-wet environment.


Crabgrass is a summer annual that germinates when soil temperatures reach a consistent 55 degrees. A crabgrass plant can produce 150,000 seeds.

Thatch Patch

Excessive watering can cause your lawn to develop a thick, spongy mat called thatch. Thatch is a layer of partially decomposed plant material, roots and stolons that forms a dense mat on the soil surface. Over-watering prevents beneficial organisms from breaking down the thatch and promotes shallow root development that leads to thatch buildup. If the thatch is more than 3/4 inch thick, it prevents oxygen from reaching grass roots and provides a habitat for fungal and insect pests. Infrequent, thorough watering helps prevent thick thatch because it promotes deep root development.


Dethatching lawn with a lawn rake in the spring garden

Insect Activity

A waterlogged lawn that promotes thatch buildup can also be an ideal habitat for insect pests. The moist layer of intertwined weeds provides a fertile breeding ground and may even offer protection from insecticides for several lawn pests. For example, armyworms and cutworms create irregular, spreading bare patches as they chew and cut grass blades at the base. White grubs, which are the larvae of May and June beetles and masked chafers, feed on grass roots and cause wilting and grass death.


Fungi may appear on a new lawn as a result of frequent watering – which is needed to aid a new sod in producing a deep root system – but will normally disappear once the interval between watering sessions increase. In older lawns, excessive thatch may prevent proper drainage and hold moisture that promotes fungal diseases. Thin, weak, reddish-orange grass is a symptom of rust fungus, which occurs in stressed lawns. Anthracnose infects wet grass at temperatures between 80 and 95 degrees Fahrenheit and causes irregular brown patches in the lawn. Brownish spots and brown, spiked fruiting structures appear on the leaf blades.

If your lawn has been affected by the negative consequences of over watering, you may need to adjust your automatic sprinkler system or consider installing a rain sensor so you aren’t watering when it rains. Over watering a lawn is much worse than under watering  because a lawn that is watered too much will starve the soil of oxygen. A good rule of thumb is if you had to open an umbrella, turn on your windshield wipers, or step over a puddle, it’s a good day to skip a round of watering.

And remember, you can always call the experts at Island Environmental for advice on any of your lawn and ornamental needs.