“What is the best organic way to get rid of whiteflies?” Question from Shawn of Kenosha, Wisconsin

Answer: Whiteflies can become awful pests to manage if the populations become large, but they are relatively easy to kill. Here is a little more information about these pests and some organic methods for handing them.

What Are Whiteflies?

Whiteflies are sucking insects that remove the juices from plant leaves and stems. Tiny whiteflies can be very destructive when populations are high–causing leaf drop and general plant decline. When plants are badly infested, the undersides of leaves will become covered with clouds of tiny flies that are bright white and clusters of their small, round, white egg masses.

Whiteflies breed continuously and quickly, which is a big reason why they are so problematic. According to Colorado State University: At 70º F, the greenhouse whitefly life cycle happens fast. “It takes 6-10 days for egg hatch, 3-4 days as a nymph I, 4-5 days as nymph II, 4-5 days as nymph III, 6-10 days for the pupa. Adults can live for 30 to 40 days.” Adults produce lots of eggs for ever-increasing numbers unless challenged.

How to Kill Whiteflies

Start by spraying the plants off with a sharp spray of water from a hose. Focus on the undersides of leaves. Then look beneath the leaves for clusters of clinging, small, white egg masses. Leaves thickly covered with egg masses should be removed, tightly bagged, and thrown away. Next, wipe the egg masses off of the remaining leaves. Make sure no eggs remain. Finally, spray the plants with insecticidal soap, Neem oil, or horticultural oil. (Click here for an overview of horticultural oils for organic insect control.) Continue to check for whiteflies and wipe and spray leaves as needed.

It may take a little work, but this method is effective.

I hope that these tips help!

Happy gardening

Jessie Keith

Black Gold Horticulturist