Backyard Mosquito Control: Start With Standing Water

Ask most people how to keep mosquitoes away from the patio and they will name a candle, a plant or a gadget. The more useful answer starts a few steps earlier, with the saucer under the geranium. The mosquitoes bothering you at dusk were very likely born within a short walk of where you are sitting, and the cheapest control you have is stopping them from hatching.

Lemon Eucalyptus Essential Oil

Our own Lemon Eucalyptus Essential Oil, in sizes from 0.5 oz to bulk.

From $9.99

Shop Now →

A mosquito needs very little water

EPA's overview of mosquitoes lists the places some species lay eggs: tree holes, old tires, buckets, toys, potted plant trays and saucers, plastic covers and tarps, and even something as small as a bottle cap. There are about 200 mosquito species in the United States, and they differ in where they breed. But the container breeders, including the Asian tiger mosquito EPA names, are exactly the ones that thrive around houses.

CDC's guidance for the home says the same thing in one sentence: once a week, empty and scrub, turn over, cover or throw out any items that hold water. Once a week is the whole trick, and it is not arbitrary. It is a rhythm, and the point is to interrupt the cycle before eggs become adults.

A ten-minute walk-around

Pick a day, say Saturday morning, and make one loop of the yard with these questions in mind. This is our own routine, assembled from the CDC and EPA lists:

Is anything holding water that does not need to? Buckets, toys, wheelbarrows, plant saucers and trash can lids are the usual suspects.
Have the bird bath, fountain, wading pool and rain barrel been emptied and refreshed? EPA says at least once a week.
Are the gutters, low spots and tarps clear after the last rain?
Do the window and door screens have gaps, and are they in good working order?

Rain barrels and water storage deserve a special mention. CDC says to cover water storage containers tightly, or use wire mesh with holes smaller than an adult mosquito if there is no lid. You can keep collecting water and still keep mosquitoes out.

Most yards turn out to have one stubborn spot, a clogged gutter or a dish under a planter. Fix that one and the rest is routine maintenance. If you suspect the source is outside your property, such as a neighbor's pool or a marshy corner, your local mosquito control district or health department is the right call.

Make the walk-around pleasant rather than a chore. Take your coffee, a stiff brush and a bucket, and move slowly enough to tip things over and look underneath. CDC says to scrub, not just empty, so give each saucer and bucket a proper going-over while you are there, then turn it upside down or tuck it under cover so the next rain cannot refill it. A hook on the fence for upturned buckets takes ten seconds to put up and saves a lot of tipping later.

Close the gaps, then cover up

EPA's tips for avoiding bites start with structure: cover gaps in walls, doors and windows, and keep screens in good order. A screened porch is the closest thing to a mosquito-free evening that does not involve anything on your skin. Next comes clothing. Long sleeves, long pants and socks, with shirts tucked into pants and pants into socks, close the gaps where mosquitoes find skin. A light cotton long-sleeve is not glamorous on a warm evening, but it is more dependable than any fragrance.

Make the porch somewhere you want to be

A screened porch works best when people actually enjoy sitting in it. A comfortable chair, a pitcher of something cold, a blanket for when the air cools and a soft lamp make an evening outdoors feel like a treat, and the screens quietly do their job in the background. Check the corners and the door edge at the start of the season, since that is where small gaps tend to hide.

EPA also mentions that yellow "bug" lights tend to attract fewer mosquitoes than ordinary outdoor lights, and is careful to add that yellow lights are not repellents. Swapping a bulb is easy, but it is a small nudge rather than a shield.

When you want a repellent

For evenings when screens and sleeves are not enough, EPA and CDC point to EPA-registered repellents, used as the label directs. CDC lists DEET, picaridin, IR3535, oil of lemon eucalyptus, PMD and 2-undecanone as the active ingredients to look for. Our comparison of lemon eucalyptus and DEET is a good place to start if you are weighing two of them.

Our own bottle is a different thing. We sell a steam-distilled lemon eucalyptus essential oil, and it is not an EPA-registered repellent, so we do not suggest it for bite protection. Registered oil of lemon eucalyptus is a refined product from other companies, which our guide to OLE, PMD and the essential oil unpacks. If your question is what to put on before the barbecue, a registered repellent from a pharmacy or outdoor shop is the answer.

We love lemon eucalyptus for its bright, green, lemony scent, and we think it belongs in the diffuser, the soap pot or on the craft bench rather than in your mosquito plan. Put your effort where it pays off: the saucer, the gutter, the screen door.

Candles, zappers and the rest

CDC's page on mosquito control at home covers water removal, screens, larvicides and outdoor and indoor insecticides. It does not discuss candles or gadgets, so we are not going to tell you they work, or that they do not. If you want a candle on the table for the glow and the scent, light it for that reason. The article on repellent sprays and mosquito devices looks at what is known about the gadget side.

Good backyard control is a bit like gardening: small, regular jobs that keep the season pleasant, and they cost almost nothing.