How to Get Rid of Whiteflies on Plants - A Quick Guide

Whiteflies are potentially crop-ruining pests that are tiny, white, and—you guessed it—fly-like. They gather in clusters on the undersides of your plants’ leaves and feed on its juices, meaning that they can render the plant unable to grow over time. They can be difficult to manage, but proper prevention and early intervention can save your crop from irreversible damage.

How to identify whiteflies

Whiteflies look exactly like their name implies. Luckily, they are more active during the day, so they’re easy to spot.

After several days of feeding, they also produce a sticky substance called “honeydew” that you can feel on the leaves of the plants. However, a good shake of your plant will give whiteflies’ presence away quite obviously—the whole colony will fly off in a frightened flurry.

Symptoms of a whitefly infestation

Whiteflies make their host plants weak over time, so symptoms of a whitefly infestation will present themselves slowly as the pests feed. Leaves will wilt and eventually become yellow or otherwise discolored. The plants’ growth is likely to become stunted.

How to prevent whiteflies

Whiteflies can be a tough nut to crack on the prevention front, but one of the best ways to control them before they even arrive is to encourage their natural predators to set up shop near your garden.

• Hummingbirds: Hummingbirds love to feed on whiteflies. Buy a hummingbird feeder and fill it with sugar water to attract these beautiful birds. They also like bright-colored flowers.
• Ladybugs: These round little bugs are attracted by bugs they can eat, but they also love dill and marigolds. Plant them around your susceptible plants to encourage a ladybug population to grow.
• Lacewings: Attract these bugs (which, as it so happens, can also help control aphids) using plants like dill or fennel.

How to control a whitefly infestation

There are effective organic and inorganic ways to cure a whitefly problem, although it’s possible that the bugs will be a yearly challenge if they’re common in your area.

Organic methods

Many gardeners swear by spraying neem oil on their plants to kill whiteflies. While it won’t kill them, you can also blast them off plants with a strong stream of water a few times a day to create an inhospitable environment—just do it early in the day while there’s plenty of sun to avoid fungal growth.

“Natural pesticides”, or pesticides created from organic ingredients, are also an option for control of whitefly populations. Products containing pyrethrum, for example, can be very effective on whiteflies and are safe for use on a wide variety of plant types.

If your whitefly infestation is concentrated to one or a few plants, remove them immediately—otherwise, they may take over your garden. This early control technique can sometimes prevent a season-long problem.

Inorganic methods

On the conventional side, there are insecticidal soaps—which can be made at home using a mixture of liquid dish soap and water or bought in the store for a more targeted recipe. These soaps are generally less toxic to humans, plants, and the environment while still killing or deterring the bug population.

Then, there are conventional pesticides. These products can either treat or prevent a whitefly infestation and may require one-time or repeated treatment. Be sure to follow the manufacturer’s instructions as precisely as possible to get the best relief from your infestation.