Skip to main content

HappySprout may earn a commission when you buy through links on our site.

Everything you need to know about permethrin garden spray, what it does, and how it helps your garden

Are there any drawbacks to this popular insecticide? Find out here.

Pests are just a fact of life anywhere there are plants around to feed them. As such, pest control is an ongoing issue for most gardeners, but it can be hard to find a spray that works for you. If you’re new to gardening or just new to the pest control aisle, you may not have heard of permethrin before. If you’re confused about what permethrin is, where it comes from, and what it’s good for, then you’re in the right place. We’re here to clear up questions you have, starting with the basics.

A person with green and white gloves sprays a pest control solution from a yellow spray bottle onto some roses

What is permethrin?

Permethrin is a compound of three chemicals based on a similar compound, pyrethrin, found in flowers in the chrysanthemum family. Chrysanthemums produce pyrethrin as a form of natural pesticide. Permethrin is the synthetic form of this natural compound, so there are some slight differences between the ratio of each chemical in the spray versus in individual plants — namely, the ratio in each individual plant can vary, but the ratio used in sprays is consistent so that you always know exactly what you’re getting.

However, most permethrin garden sprays are not 100% permethrin. Permethrin is typically used as the active ingredient, but another chemical is added to extend its lifespan and make it more effective.

How is permethrin used?

Permethrin is available mainly in sprays, although some concentrates are available. The most common use for permethrin sprays is to spray it on a cloth to keep insects, especially mosquitoes, at bay during long hikes or gardening sessions. The permethrin soaks into the cloth and kills pests when they land on it.

It’s important to read the instructions that come with any pesticide you use, and permethrin sprays are no exception. Some permethrin sprays are made specifically for cloth, while others may not be safe for indoor use or may be designed for an overall lawn misting rather than for use directly on garden plants.

What pests are permethrin effective against?

Permethrin is effective against a wide range of insects, including ticks, mosquitoes, lice, mites, cockroaches, fleas, and flies. It works by interfering with the neurons of impacted creatures, causing paralysis and death. It does this on contact, meaning it keeps pests from nibbling your plants in the first place. It is even used in treating mosquito netting and is a main ingredient in some flea collars for dogs, although it isn’t safe for cats.

What are the drawbacks and limitations of permethrin?

In addition to killing pests, permethrin can also harm or kill beneficial insects, such as bees and other pollinators, and cats. If enough of it contaminates a body of water, it can negatively affect fish and other aquatic life. There are a few precautions you can take to limit the potential harm, though. Using permethrins on indoor plants, for example, can reduce both the number of pollinators exposed to it and the amount of pesticide that can potentially find its way into waterways. If you have a cat, keep your plants in an area your cat can’t access.

If you have outdoor plants that you plan on using permethrin on, you can use a pollinator net to keep pollinators away from your plants. You may be able to cover the blooms with a bowl and target the leaves with your spray, but this isn’t a foolproof plan.

Raised gardens with nets over the plants
Image used with permission by copyright holder

Where can you find reliable permethrin spray?

Your local gardening supply store will likely have several different permethrin sprays available, but if you prefer to get yours online, or if you’d like to go into the store with an idea of what brands to look for, here’s what to look for.

Before buying a permethrin spray, it is important to check what it’s designed to be used on. Many permethrin sprays are designed for use on cloth specifically, which is great if you’re looking to set up netting or a cloth barricade around your plants. However, this isn’t ideal if you just want something to spray on your plants.

One of our favorite multi-use products is Voluntary Purchasing Group Inc.’s Hi-Yield Lawn, Garden, Pet and Livestock Insect Control . It is a concentrate, not a spray, so you need to read the instructions carefully, but it does have a greater range of applications. One bottle can make quite a few batches of spray as well, meaning you won’t need to get additional bottles very often.

It’s important to remember that every pesticide has its benefits and drawbacks, and it’s up to you to decide which pest control method is right for you and your plants. A lot of pest controls boil down to trial and error, and permethrin is one of many options. Give it a try and see what you and your garden think!

Editors' Recommendations

Cayla Leonard
Cayla Leonard is a writer from North Carolina who is passionate about plants.  She enjoys reading and writing fiction and…
Are you asking, ‘Why is my tomato plant wilting?’ Here’s how to be the hero in your garden
Properly water and inspect your tomatoes to prevent (or treat) wilting
Tomatoes on a tomato plant

Tomatoes are probably the most popular veggies grown at home. Even novice growers can grow these plants with little to no experience in growing anything. Even better, many of these beginners are successful because tomatoes are so easy to care for and grow in your own home. However, one of the most common questions about growing tomatoes is, "Why is my tomato plant wilting?" Well, it could be due to a few reasons. We'll take a look at them here and give you tips on how to get your tomato plants back into tip-top shape. 

Why do people grow tomato plants?
Let's first talk about why you want to grow tomato plants. Growing tomatoes at home has a lot of benefits. First, they're healthier than store-bought tomatoes, and they taste better, too! There's no denying that tomatoes grown at home have a richer flavor. Once you eat your own tomatoes, you'll likely find the store-bought ones flat and watery by comparison.

Read more
This is how to know when to harvest your peas for maximum flavor and crispiness
Find out when your peas are just right for the picking
Organic green sugar snap peas

If you're looking to start a vegetable garden or just add to the one you already have, consider growing peas. These green pods are some of the easiest spring vegetables to grow — they even work as indoor vegetables. They tolerate cold temperatures and moist conditions quite well and don’t need much fertilizer to thrive. Best of all, their crisp texture and sweet flavor make them versatile veggies in the kitchen. The only thing that's tricky about growing peas is knowing when to time your harvest. If you're having trouble figuring out when to harvest peas, keep reading to know when to get the freshest, sweetest, and crispest peas.

Quick tips on growing peas
Even before you get to harvesting, you want to care for your peas so they grow healthy, strong, and delicious — luckily, they're pretty low-maintenance vegetables. Here are some tips to start your pea-growing journey:

Read more
When do banana trees produce fruit? What you need to know
Your guide to banana harvest times
Banana tree with ripe fruit

Bananas are a delicious, nutritious, and versatile fruit. If you’re a fan of bananas, you might be interested in growing your own banana tree. These tropical trees can be grown easily in greenhouses for a hearty harvest of bananas. Once you've planted your banana tree, you might be wondering when do banana plants produce fruit? If you're starting to get impatient, then we have the solution! We’ll answer all your banana questions so you know what to expect from your banana tree's harvest.

How long does it take banana trees to mature?
Banana trees are interesting, as they aren’t technically trees. They're actually herbaceous perennials, which is helpful since we no longer grow bananas from seeds. Instead, the roots of a banana tree send up a sucker, or smaller but still attached, plant. These suckers are then separated from the parent tree and planted elsewhere, to grow into a mature plant on its own.

Read more