The mosquitoes that carry the Zika virus have evolved to reproduce in the smallest amounts of collected water, even in bottle caps. Yards and landscapes tend to have more than enough water sources to support a growing mosquito population. As annoying as that situation is on its own, it could now also have the potential to contribute to the spread of Zika in the United States.

Mosquitoes prefer to lay eggs in stagnant and shallow water, so if a landscape has a pool or pond, it’s best for it to be relatively deep and to have a fast-working filtration and circulation system.

Some potential breeding grounds are obvious. Old tires, buckets and abandoned swimming pools or ponds are all prime real estate for the insects. Other areas where they can grow are not as apparent: corrugated PVC drainage pipe, a clogged gutter, a soda can buried in a rug of ivy, even folds in the tarp over the woodpile.

Rainwater harvesting systems, whether a simple barrel, a rain garden or more, pose a very common risk for mosquito growth. If gardens or detention areas don’t drain within 48 hours, the mosquitos will most definitely find them. Barrels and storage tanks of any size need to have a screen over any openings. Mosquito dunks, which contain a larvacide called bacillus thuringiensis, is another good preventative measure.

Bird baths are another problem area. They can be very attractive features on a client’s landscape, but you cannot neglect them. The water needs to be changed every two to three days. If the bird bath is going to sit for more than a week, it should be flipped over or stored under a cover.

As the growing season approaches, spend a moment or two thinking about other potential breeding areas for mosquitoes this summer. Even if Zika doesn’t become a major threat this side of the border, your clients will be happy to have fewer mosquitoes regardless.