Mosquitoes in Gutters in Florida: How Clogged Gutters Breed Them and How to Stop It

Mosquitoes lay eggs in still water. A gutter qualifies when:

Wet leaves and organic debris also feed larvae. A gutter that stays wet for more than a few days after rain is a candidate.

• Debris blocks flow, so water sits in the trough
• Pitch is wrong, leaving a low spot that holds water
• Downspouts clog, backing water up
• Guards or mesh clog, trapping water above the trough

From a ladder or an upper window, check for:

The Florida Department of Health has information on mosquito-borne illness and prevention, and local mosquito control districts can advise on breeding sites.

• Standing water in the trough more than a couple of days after rain
• Wriggling larvae in a pool of water
• A swarm of mosquitoes near a particular section of roof
• Debris mats or plants growing in the gutter

Follow the steps in order:

• Clean the gutters and remove all debris
• Flush the runs with water and confirm they drain to the downspouts
• Fix pitch. Re-hang sagging sections so they slope toward the outlet. See sagging gutters in Florida.
• Unclog downspouts and check the elbows
• Check guards. Mesh clogged with pollen or debris can trap water.

• Clean on a schedule. Twice a year at minimum, more under trees. See how often to clean gutters in Florida.
• Check after big storms, when debris and water accumulate
• Keep downspout outlets clear and draining away from the house
• Consider guards if your trees make cleaning frequent

If you collect roof water in a barrel, use a fine screen on the inlet and a sealed lid so mosquitoes cannot get in or out. See rain barrels in Orlando.

Gutters are one source. Also empty flowerpot saucers, buckets, birdbaths, and anything else that holds water for more than a few days. Dump and scrub weekly.

If you cannot reach the gutters safely, or if water keeps standing after cleaning, a pro can find the cause. See gutter cleaning and gutter inspection. Do not use chemicals in gutters without advice, since runoff reaches the ground and landscaping. The University of Florida IFAS Extension has resources on mosquito management in the home landscape.

Central Florida's warm, wet climate supports mosquito activity for most of the year, and the wet season adds standing water everywhere. A gutter that holds even a small amount of water after every rain gives them a nursery close to your windows and doors. Debris in the trough feeds larvae, and shaded, sheltered gutters stay wet longer.

You do not have to climb to look. From an upper window or a stable ladder placed safely, check the trough a day or two after rain. If water is still standing, or you see a dark mat of debris, treat it as a problem. A hose test also works: run water into the gutter and watch whether it drains fully and quickly.

After you clean and fix pitch, keep watch:

If mosquitoes remain a problem, look at other sources around the yard too. The Florida Department of Health publishes guidance on reducing mosquito habitat. For more on schedules, see gutter cleaning cost in Orlando.

• Check the gutters two or three days after each heavy rain in summer
• Clear any new debris quickly
• Watch for standing water at low spots
• Keep downspout outlets clear of leaves and mud