Is Wasp Spray Harmful To Plants?

by Derrick | Last Updated: September 7, 2021

Wasps can be highly beneficial insects since they prey on others and pests that might destroy your garden. Nevertheless, they can become incredibly disturbing, especially if you disrupt their habitat or nest , and you might rely on a wasp spray to get rid of them. However, are they harmful to your plants, and what would be the severe effects?

Wasp spray is highly toxic and some may argue it is not safe to use for your vegetation.

They usually contain pyrethrin or any pyrethroids as their primary ingredient, which are naturally found in chrysanthemum flowers. It is often used to help keep fleas and other pests away from your plants.

This article will cover all sorts of information related to wasp spray, their toxicity and effects on plants, how to get rid of wasps, what are some better alternatives, along with how to make a safer repellent naturally in order to keep your garden beautiful and free from pests and harmful chemicals.

Wasp Spray Properties

Before diving into the potential reasons why wasp deterrents may be toxic for your plants, we need to comprehend what ingredients it contains that make them harmful.

The main organic compound found on these pesticides is called pyrethroids which are a group of artificial insecticides and often produced by the flowers of Pyrethrins or commonly known as Chrysanthemum or Tanacetum. They are used as a harsh chemical that kills all sorts of insects and pests almost instantly, including mosquitoes. It can be beneficial and an essential tool to prevent the spread of various viruses.

Why Is Wasp Spray Harmful To Plants?

As we saw previously in this article, Wasp pesticide can come in handy in situations where the nest of these insects is interfering or endangering. However, pyrethroid-based wasp deterrents can be harmful and toxic for plants since they may cause damages under certain conditions. It is usually explicitly told on their warnings not to spray the product straight to the foliage. Another characteristic of this chemical compound is that they tend to break down slowly in the ecosystem. This can often be viewed as a good quality for insecticides, but it has detrimental effects on the environment since these tend to linger for days or weeks once applied.

On the other hand, pyrethrin-based insecticides are toxic, but their persistence breaks down quickly once exposed to air and moisture. It is considered relatively less poisonous and biodegradable in comparison to other compounds. However, when used, one of the most expected effects is photosensitivity leading to burnt leaves, damaging new growth, and more.

What Effects Does Wasp Spray Have on Your Garden?

Regardless of their general effectiveness and renowned benefits, plants and the ecosystem might react differently since most of these pesticides contain harsh and toxic chemicals that can be damaging to them.

Since wasp sprays are usually made of pyrethroid compound, this chemical can have some negative effects on your garden, such as:

  • Affects photosynthesis performance, according to research conducted in Hungary by the Department of Plant Biology.
  • It may cause the accumulation of saccharides (carbohydrates), which might attract and generate the colonization of insects or pests.
  • Even though it has a relatively lower toxicity percentage, it can still cause some burns to the plants’ foliage.
  • A sudden decrease or decelerated plant growth.
  • In extreme cases, it may kill the plant
  • It may eliminate important insects for the ecosystem.
  • It takes around fourteen to seventeen days for wasp spray to break down entirely.
  • There is evidence that pyrethrin adheres to the soil between two and nine days.

After discussing some potential side effects of using wasp sprays or any insecticides, we will discuss some good benefits.

  • It is relatively safe to use near vegetation or gardens.
  • A great and efficient tool for dealing with pests.
  • Known for knocking down insects instantly.
  • It is biodegradable, which means that it breaks down pretty quickly unless there’s an absence of light and it is disintegrating in water.
  • Wasp spray repels wasps and any other pest for around thirty days.

Is Wasp Spray necessary?

First, we need to know that we don’t need to buy expensive or fancy pesticides to have beautiful and healthy plants. The reason being is that they may be counterproductive. In other words, they may alter Mother Nature’s natural balance, making your garden prone to more diseases. Instead of killing off wasps that are not bothering you sometimes, it is best to leave them alone if they haven’t stung anybody. Some gardening enthusiasts view them as natural pest repellents since they are considered ecologically vital predators and valuable pollinators.

While it is undeniable how wasp repellent can come in handy to get rid of their nest there are some different ways to eliminate them in a way that doesn’t harm the plants directly.

How To Safely Use Wasp Spray

As stated earlier in the article, wasps are beneficial since they feed off of insects and are excellent pollinators. Although they are essential for the environment, using wasp spray is a standard solution when you have aggressive and unwelcome wasps that built their nest near your house or in your garden.

Before buying a can of wasp spray, make sure to review these tips to eliminate them safely and efficiently without harming your plants:

  • Spray at sunrise or dusk: the reason being is that wasps are less active during this time, and it is far more effective. to ensure all of them are in the nest at the time of the attack.
  • Spray directly to the nest: to prevent harmful effects or potentially damaging your plants, make sure to focus your spraying on the actual nest to make it more efficient, instead of spraying one wasp at a time that you might encounter. Be careful since these types of pesticides are meant to be used outdoors only.
  • Location is critical: taking into consideration where the nest is situated is essential before planning your attack. If it is located extraordinarily high and requires you to use a ladder, it is best to plan and seek an easy escape route if they swarm you. In those exceptional cases, it is suggested to contact a pest control professional. If it is a small and visible nest, then a wasp spray from a certain distance would do the job. A safe space to propel from is about twenty feet.
  • Wear protective clothing: if you don’t use proper gear, you are prone to pain, allergic reaction, and the discomfort of a wasp’s sting . In this case, wear long jeans, boots, a hoodie, and gloves. In addition to this, if you’re using wasp spray, it is best to use old clothes that you no longer care about since the smell may cling onto the fabric and damage it.
  • Be mindful of your surroundings: make sure that when you use the pesticide, you don’t have any dogs, cats, or children exposed since it can be highly poisonous for living things, especially aquatic animals.
  • Propel in the direction of the wind: be aware of the wind’s direction. An ideal spray would be having the blow of air at your back and not towards your face. Also, make sure it doesn’t go to any exposed eating areas like patio tables, grills, etc.
  • Wash your hands after: this is helpful to get rid of any poisonous chemical leftover.
  • Prevent wasps from coming again: as you may know, even if you spray their nest, there is a high chance they will return. It is best to destroy or knockdown abandoned nests so they can’t build a new one. Another great idea is to seal cracks around windows and doors.

Natural Wasp Repellents

There are other alternatives to wasp spray that are more organic and less toxic. Here are a few of them:

  • Grow naturally repellent plants: such as lemongrass, sage, rosemary, citronella, clove, fennel, chamomile, wintergreen, pennyroyal, basil, geraniums, wormwood, eucalyptus, marigolds, etc.
  • DIY Wasp Spray:
    • A very popular way to eliminate wasps is by using equal parts of water and white vinegar in a spray bottle.
    • Others use chili peppers and combine them with three cups of water.


Wasp spray itself, just like any pesticide, can be toxic to the environment due to its potentially poisonous chemicals . Depending on which one you choose, some are more biodegradable than others, but the proneness to harming your beautiful garden is still there. That is why it is recommended to use them when you have aggressive wasps in your home, or you want to get rid of their nest.

A great piece of advice is to spray directly to the nest at night when they’re less active. That way, it is safer, and you won’t be damaging your plants.