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Down the Garden Path

Mosquitos in the Landscape

Mosquitos are adjusting to our ever-changing weather patterns just like our plants in the home landscape this season. May into June would be our traditional time mosquitos start show up for the summer. This season, April had the rain and not May, so mosquitos can be behind a bit.

Mosquitoes favor warmer temperatures and the right kind of water – permanent, floodwater or stagnant, depending on the species. Permanent bodies of water include ponds and lakes. Floodwaters are retention ponds that are dry most of the time and natural low-lying areas. Stagnant water examples are those clogged gutters, garden structures that can hold water and bird baths.

When the water is cooler, development is slower and larvae will succumb to natural diseases, reducing the numbers that make it to adulthood. We have had the warmer temperatures recently but not the standing water or stagnant water so far. Permanent water mosquitos are not the ones that show up in large numbers.

Homeowners tackle mosquito management on a number of fronts. Not just for mosquito management, but cleaning and clearing the gutters for the next rain event will prevent water damage to the home too. You may wonder "How could a gutter be plugged up already?" yet spring bud scales and flower parts from our big trees can fill it quickly. If there are any parts of your yard art that hold water or parts that collect water, think mosquitos. If those areas dry out within a week, you are ok. Birdbaths should be flushed about one a week to prevent mosquito larvae from turning into biting adults and to provide clean water for the birds.

Gardeners also can incorporate some of the mosquito repelling plants into the flowerbeds. These help in the overall effort to reduce biting mosquitos, but alone, will not do the job. Plants like catnip, basil, scented geraniums and lemongrass will be advertised to repel mosquitoes and other insects.

Often the floodwater mosquito is the one giving us the large number of mosquitos about two weeks after a rain event. They are noisy, buzz around our face, can fly very well and can come from a good distance. So even with empty gutters and clean birdbaths, they can be very bothersome while we are outside.

Other options for mosquito management will be the use of clothing treated to repel mosquitoes, or applying a number of sprays or lotions that repel insects. These can be natural oils or synthetically based. They can be effective for as little as an hour or can last for several hours. None are likely to last the day with just one application.

Lastly, mosquitos are attracted to body heat, carbon dioxide and dark clothing. So, think twice when choosing your gardening outfit, as you don't want to paint a mosquito bullseye on yourself.

Richard Hentschel is a Horticulture Extension Educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. Stay tuned to more garden and yard updates with This Week in the Garden videos at and the Green Side Up podcast at The Kendall County Master Gardener Help Desk is open for 2018. Current hours are Monday through Friday from 9 a.m. to 12:30 p.m. at 630-553-5823.