Wasps are crucial parts of a healthy ecosystem. They control pest insects and pollinate flowers. However, they are also known for their disagreeable habit of stinging people, some of whom are allergic to wasp venom. Their attraction to sugary substances makes them an unwelcome guest at picnics and around garbage bins, where they may sting in defense of their food. For these reasons, some people may wish to keep them away. They are so useful, though, that killing them is not advised. Here, we will cover several plants you can use to repel wasps. If you make your yard or garden unattractive to wasps, they will simply find a different place to nest and hunt. There aren’t many plants that repel wasps, simply because wasps are pollinators, so many plants produce substances that attract, rather than repel. However, naturally-repellent plants exist and include mint, wormwood, lemongrass, citronella, clove, pennyroyal, sage, rosemary, geranium, chamomile, thyme, fennel, wintergreen, and sweet marjoram (Origanum majorana). Cucumber peels may also repel wasps. If you want to kill wasps naturally, insectivorous plants will do the trick. We will also cover plants that are advertised to repel wasps but don’t, including eucalyptus, basil, and marigolds.
Of the plants that keep wasps away, research has only determined how some of them work. The repellent properties of plants lie primarily in their oils. Essential oils of spearmint, peppermint, and ginger mint (Mentha arvensis) have been shown scientifically to repel yellow jackets and paper wasps, as have those of the plants mentioned above. In peppermint oil, this may be due to the presence of the chemical menthone, which also repels yellow jackets and paper wasps. American wintergreen (Gaultheria procumbens) contains the chemical methyl salicylate, another repellent chemical. In fact, methyl salicylate is responsible for the scent of wintergreen, a scent that resembles that of some mint plants. So, if you’re wondering what scents repel wasps, minty ones are a safe bet. Wormwood oil kills worms and insects, which explains why wasps would avoid it. In a study, mixtures of essential oils were found to work better than individual oils. The best mixtures for repelling yellow jackets and paper wasps were clove + geranium + lemongrass and clove + geranium + lemongrass + rosemary. While the wasp repellent plants themselves will not be as strong as the concentrated oils tested in the studies, they will still help and should be cultivated in areas where wasp activity is unwanted.
Spreading cucumber peels around may keep pests, including wasps, ants, silverfish, mites, and moths out of certain areas. Though this property has not been scientifically tested, it is likely due to a bitter chemical within cucumbers called cucurbitacins. In insects that feed on vegetation and detritus, cucurbitacins deter both feeding and egg-laying, which suggests the potential for true repellent properties.
There are three general categories of carnivorous plants: Venus fly traps, pitcher plants, and sundews. They are all capable of devouring wasps. However, they are indiscriminate feeders. Some are even large enough to eat other animals, such as frogs. So, be aware that if you plant carnivorous vegetation, it will eat other insects and maybe even some birds, reptiles, and amphibians. Venus fly traps (Dionaea muscipula) have leaves with clam-shaped traps at their ends. Within each trap are three trigger hairs. If two trigger hairs are touched or one hair is touched twice in quick succession, the trap snaps closed, and digestive juices break down the plant’s prey. Pitcher plants (genera Sarracenia, Darlingtonia, Heliamphora, Nepenthes, and Cephalotus) have a different strategy. Their leaves are shaped like pitchers and hold water. When insects fly down into them to drink, they become trapped, drown, and are digested. Finally, sundews (Drosera spp.) have tiny, sticky hairs all over their leaves that trap insects much like flypaper. Unlike fly paper, sundews secrete digestive juices onto the leaves to break down their meal. One particular pitcher plant in France (Sarracenia sp.) selectively consumes the Asian hornet, an invasive that eats native bees. This pitcher plant doesn’t seem to eat European hornets, other wasp species, or bees.
Finally, in your research, you may run across articles stating that eucalyptus, basil, and marigold are also natural wasp repellants. However, social wasps have been collected from eucalyptus plantations and solitary parasitic wasps have been used to save eucalyptus trees in California from an insect called the eucalyptus longhorned borer. In addition, one basil species, far from repelling wasps, is especially attractive to them. The flowers of the African blue basil, a cross between the East Asian camphor basil (Ocimum kilimandscharicum) and the common sweet basil (O. basilicum), are favored by pollinators, including wasps. While the camphor basil produces insecticidal substances, these are produced in the leaves as a defense mechanism against herbivores, not in the flowers where pollinators may be harmed. Marigolds are also known for their attractiveness to pollinators, including wasps, bees, and butterflies.
Despite the benefits wasps provide to our gardens and the planet as a whole, they can become nuisance pests, especially to those with bee and wasp allergies. Here, we present several non-lethal options for controlling wasp populations in your yard or garden (plants that deter wasps, cucumber peels) as well as one lethal option (carnivorous plants). We also dispel some myths about plants purported to be wasp repellents that may end up attracting them instead. We hope that this guide proves useful to those hoping to keep wasps away from their patios this summer.