With more and more information available about how destructive pesticides are, gardeners and farmers alike search for ways to naturally repel pests. This includes the whitefly, a tiny insect that sucks the vital juices out of a variety of plant leaves and stems.
Luckily, Mother Nature has provided everything we need to keep pests such as the whitefly away. In this article, we’ll take a look at whiteflies—what they are, why we consider them pests, and how we can use other plants to naturally repel them.
What are Whiteflies?
True to their name, whiteflies are tiny, white- or cream-colored winged insects. However, they are not actually a type of fly. They are so named because they have the capability to fly and look a little bit like flies).
In fact, whiteflies are more closely related to mealybugs or aphids, and there are approximately 1500 species of whiteflies, though they all tend to behave fairly similarly. They are triangular and are around ½-inch to 1-inch in size.
The most common types of whiteflies in the United States are typically the greenhouse whitefly, the sweet potato whitefly, and the banded winged whitefly. All are harmful to plants commonly grown in gardens. Let’s take a look at why.
Why Do You Need to Repel Whiteflies?
It’s certainly true that not all insects are harmful to plants. In fact, many are essential to maintaining healthy biodiversity in our ecosystems, both small and large.
That said, whiteflies often need to be kept away because they infest and destroy certain plants. They attach themselves to leaves and sometimes stems and then literally suck the life out of them by taking vital juices. They also transmit diseases that kill many varieties of plants, making them even more threatening to a healthy garden.
If you’re interested in where whiteflies come from, more on that here.
To make matters worse, whiteflies can become invasive, and dealing with an infestation is not fun. In warmer climates, they can breed all year long; during hot summer months, it only takes about two weeks for eggs to fully mature, meaning that an infestation can quickly become an out-of-control population of whiteflies.
Female whiteflies can produce as many as 400 viable eggs in their short lifetimes.
They can also become unwanted houseguests since they can’t survive very cold winters outdoors, so they sometimes invade greenhouses or feed on indoor plants during colder months up north.
Which Plants Do Whiteflies Like?
Whiteflies are especially attracted to tomato plants and are notorious problems for tomato growers all over the country. If you grow tomatoes or hope to add tomatoes to your garden, it’s wise to prepare for whiteflies by planting something they do not like alongside them.
In addition to tomatoes, whiteflies also enjoy eggplants, sweet corn, peppers, okra, cabbage, sweet potatoes, and citrus. Since tomatoes are frequently grown in gardens that also have some of these things, it’s a veritable playground for whiteflies.
Interestingly, whiteflies also seem to be attracted to the color yellow, as well as close shades of orange and red. Pay attention to whether flowers and other plants of this color might be drawing whiteflies to your garden.
How Do You Know You Have a Whitefly Problem?
The most obvious way of knowing that you have an infestation of whiteflies is by seeing them; they are usually large enough to be readily visible to the naked eye. They are most active during the midday (they are sluggish in the morning), and their distinctive white color makes it very easy to see them against green leaves and dark dirt.
Whiteflies prefer new leaves, so check those first if you think you may have a problem. Look on the undersides of leaves, where you may also find eggs or larvae. Be aware that when you begin checking, the whiteflies may fly away in a swarm.
Besides just noticing them, you may also start to see a substance called honeydew on the leaves of some plants.
This sticky and sweet substance can eventually become food for ants and fungi, making whiteflies even more problematic. If you notice an influx of ants in the vicinity, that may also be a sign of whiteflies. Honeydew won’t appear for at least a few days after the whiteflies begin feeding, so if you see it, you may already be too late for preventative measures.
Finally, you’ll also notice evidence of whiteflies on your plants themselves. Leaves will turn a pale green or yellow color and wilt before shriveling or falling off entirely. Eventually, the entire plant may die.
Plants That Repel Whiteflies Naturally
Luckily, there are several plants that you can use to keep whiteflies away naturally. Some of them are also useful to your garden in other ways, as well. Let’s take a look at the seven best plants for repelling whiteflies.
You may think you haven’t heard of this type of flower before, but that’s because it is a very broad classification that includes some much more common flowers and plants.
Types of artemisias include mugwort, sagebrush, and wormwood, although there are several hundred types of these plants.
They are typically fragrant (you can extract their oils to make your own essential oils) and herbaceous, though they produce a bitter taste that is unappealing not only to whiteflies but several other types of insects as well. Some have described it as an antiseptic smell.
The fact that these plants are almost universally hated by bugs makes them great additions to gardens. They will attract butterflies and moths, though. These can act as important pollinators, though moth caterpillars in particular sometimes eat leaves of plants.
While the leaves are very fragrant, most types of artemisias are far too bitter for human consumption. One exception is tarragon, a lovely addition to many French dishes in particular.
Is there anything tastier than a fresh basil leaf on top of a ripe sliced tomato? Another perfect reason to plant basil in your garden is that whiteflies really do not like basil. Basil will also repel the tomato hornworm, keeping your tomato plants even safer.
However, it is important to be aware that some bugs like basil, and you may find more of them if you plant a lot of them. These include certain types of slugs and Japanese beetles.
To grow basil, you need very moist soil, so be sure to water often. Basil plants need plenty of sunlight. You also need to pinch back the leaves from the top of the plant to prevent them from going to seed and continue to see large, flavorful leaves.
This plant has been used in cooking and medicine throughout south and central America for centuries. Its other names, which are more commonly used in the United States, are wormseed, skunk weed, and goosefoot. It has a very strong aroma and taste (one that can sometimes be off-putting for humans as well), almost petroleum-like. That’s what makes it a good deterrent for whiteflies and other insects, such as ants.
Generally speaking, marigolds are wonderful flowers to include in your garden because they repel many insects, and they are very pretty. No matter what you grow, it is a very good idea to plant marigolds somewhere in your yard or garden for their repellant properties.
Marigolds are even useful for getting rid of slugs, too! More on that here.
In fact, French marigolds are toxic to nematodes and their eggs, which can become serious problems in a garden. Ants, which are harmful and annoying for a number of reasons, hate marigolds as well.
Like most plants, something is bound to feed on them. You may see more spider mites or snails after you plant French marigolds. Birds eat them, too, so be aware that they can also get into your garden and eat some of your plants because you planted marigolds.
Like French marigolds, nasturtiums are great for repelling insects. In addition to whiteflies, nasturtiums will keep away aphids, cucumber beetles, and squash bugs. Deer and rabbits don’t like them either.
There are about 80 varieties of nasturtiums, both annuals, and perennials. They have particularly vibrant, bright colors, and the blossoms are edible, so they make lovely additions to salads. Try to avoid yellow nasturtiums for whiteflies. They taste sweet and peppery and are also good for making sauces and dressings.
We’ve already mentioned several plants that are peppery and highly fragrant, which are good for repelling whiteflies, so it should come as no surprise that peppermint is also good for this purpose.
Peppermint is known as “nature’s repellent” in that its oil works as a deterrent for countless animals and insects. More specifically, it’s an extremely powerful raccoon repellent as well.
Animals that eat peppermint include rabbits, aphids, slugs, and snails. Remember that aphids do not like nasturtiums, so this is a good reason to plant them both, along with peppermint/
Yet another common herb that is good for keeping whiteflies away is thyme. Once again, it is the smell and taste of these plants that are unappealing for them. And they’re not the only ones; thyme also repels cabbage loopers, cabbage maggots, corn earworms, tomato hornworms, and small whites. It can also be used to make an effective mosquito repellant. Aphids like it, however.
There is certainly an art and science to the right combination of plants in your garden to both suit your culinary cravings and protect each other to create a healthy, thriving, mini-ecosystem.
Other Ways of Preventing Whiteflies
Whiteflies are notoriously difficult to get rid of, so that’s why it’s so important to take preventative measures to protect your garden, besides just planting things they do not like. Let’s look at a few of them:
- Check plants before bringing them home: before you purchase a plant from a garden center, check the leaves carefully for evidence of whiteflies (and other pests).
- Don’t use insecticides: these toxic products do not differentiate between helpful and harmful bugs. They also kill ladybugs and spiders, which are natural predators of whiteflies. What’s more, whiteflies can actually survive many common insecticides. Chives, dill, and marigolds will all attract ladybugs.
- Attract predators: in addition to ladybugs and spiders, dragonflies and hummingbirds are also natural predators of whiteflies. Sage and catnip both attract hummingbirds and providing sources of water and places to rest will help attract both hummingbirds and dragonflies. There are also species of wasps that lay their own eggs inside the eggs of whiteflies, killing them. These wasps are very small and do not sting humans.
- Use reflective mulch, which makes it difficult for whiteflies to find their preferred plant foods. Or lay reflective surfaces on the ground underneath vulnerable plants.
- Hang sticky traps. The downside is that other beneficial flying insects may become trapped as well, but they aren’t as dangerous as pesticides and insecticides.
- Pruning: As part of any effective gardener’s list of chores, you can remove infested leaves or portions of the plant. Just be sure to completely dispose of them (do not compost) in order to prevent the whiteflies from returning.
How to Get Rid of a Whitefly Infestation
More than likely, if you have an infestation of whiteflies, you’re going to need to do a little bit more than just plant some repellant herbs in your garden. Let’s look at some natural ways of dealing with an existing infestation of whiteflies.
The first thing that you should do is identify the severity of the problem. Inspect your plants carefully to uncover the extent of the infestation. Once you do that, follow these steps:
- Use your vacuum. Depending on the extent of the infestation, this may be a long and tedious process, but it is certainly worth it.
- Empty the whiteflies into an airtight container (such as a plastic bag). Dispose of this completely.
- Prune the most damaged leaves and branches, and even entire plants if need be.
- Apply a soap solution.
- Plant whitefly repelling plants. Any of the above will work, but consider the other needs of your garden.
- Utilize plants that will attract ladybugs, bees, or other natural predators of the whitefly.
- Periodically spray your plants with soap and water.
Other Simple Ways to Treat Whiteflies
In addition to vacuuming, you can also try to spray away whiteflies. Use a regular garden hose to spray for whiteflies, which will fly away when blasted. This won’t stop them from coming back, but it clears them out so that you can take other measures. In addition, doing so regularly creates an inhospitable environment for them.
You can also use a simple combination of dish soap and water to control whiteflies, as we mentioned above. Add a good squirt (about ½-1 teaspoon) of dish soap (Dawn is safe for animals and much less toxic than some other brands) to a gallon of water. Shake it well and add to a spray bottle. Be sure to use this method when temperatures outside aren’t too hot; late in the day is best.
If neither of these tactics seems to work for temporarily ridding your plants of whiteflies, you can vacuum them on a more regular basis. Gently and carefully use a vacuum hose or other attachment to trap the whiteflies, larvae, and eggs. Do not empty the vacuum contents inside your house!
Key Takeaway: Prevent Whiteflies Before They Infest Your Garden
The best way to deal with whiteflies is to prevent them from becoming a problem in the first place. As you have seen, there are several tasty and attractive plants that can be used to repel them, especially if you plan to grow tomatoes or another plant that whiteflies love; grow some whitefly-repellant plants alongside them.
Master Gardeners of Ventura County. “Controlling Whiteflies in Your Garden.” University of California, Division of Agriculture and Natural Resources. https://ucanr.edu/sites/VCMG/Controlling_Whiteflies_in_Your_Garden/
Old Farmers Almanac. “Whiteflies.” https://www.almanac.com/pest/whiteflies
Schlaeger, Stefanie, John A. Pickett, and Michael A. Birkett. (2018). “Prospects for management of whitefly using semiochemicals, compared with related pests.” Pest Management Science 74 (11).
Van Lenteren, J.C., and L.P.J.J. Noldus. (1990). “Whitefly-Plant Relationships: Behavioural and Ecological Aspects. Department of Entomology, Agricultural University, Wageningen, The Netherlands.
White, Jen. “Whitflies in the Greenhouse.” Entomology at the University of Kentucky. https://entomology.ca.uky.edu/ef456