Skip to main content

Is Epsom salt good for controlling garden pests?

Find out if Epsom salt keep pests away

Since the beginning of agriculture, garden pests have been, well, pests. Many solutions to this problem have been invented, touted, and debated — from organic pest control methods to chemical ones. One such solution is Epsom salt. Epsom salt makes for wonderful and relaxing baths, but can it help protect your plants from insects? Here’s what you need to know before adding it to your routine.

Hand in a brown and white glove holding a pile of Epsom salt next to an evergreen tree
Martina Unbehauen / Shutterstock

Does Epsom salt keep pests away?

Using Epsom salt for pest control purposes is something many gardeners swear by, and there are several ways it has been traditionally used in the garden. There are some more recent scientific studies showing that Epsom salt may not be as helpful as people believe, although it can be effective for pest control indoors. However, the anecdotal evidence in favor of Epsom salt is strong. If you’d like to try it out for yourself, here are the most common ways to use Epsom salt in your garden.

Recommended Videos

Dilute 1 to 2 tablespoons of Epsom salt in 1 gallon of water. It may not seem like a lot, but Epsom salt is very concentrated, so it doesn’t take much. Water your plants with Epsom water instead of regular water once or twice a month. Since it can help plants better absorb nutrients and be stronger and healthier, the idea is that a stronger plant can more easily defend against or recover from pests.

You can also sprinkle a line of dry Epsom salt around the edge of your garden, between rows in your garden, or around individual plants. This is intended to defend against slugs and beetles in particular.

Can too much Epsom salt hurt plants?

Epsom salt can provide a lot of benefits, but it can also hurt your plants. It all depends on the magnesium content of your soil. Magnesium helps plants absorb nutrients and produce chlorophyll. Epsom salt is magnesium sulfate crystals. If your soil is deficient in magnesium, then adding a small amount of Epsom salt occasionally can help your plants create bigger blooms and greener leaves. However, plants need a balanced diet, so if your soil already has plenty of magnesium, adding Epsom salt can throw off the balance of your soil and cause problems for your plants. It can even kill plants over an extended period of time.

Purple, pink, and white hydrangeas
soo007 / Shutterstock

What pests does salt kill?

Salt is notorious for the way it affects slugs and snails, but those are not the only pests it kills. Salt can kill cockroaches, although it isn’t the most effective way to deal with them. Cockroaches can eat and interact with salt safely, but salt can drown them and kill them.

Have you ever wondered if Epsom salt can kill termites? The answer is yes, salt, even Epsom salt, can kill these creepy pests. Pouring saltwater with a high salt content into termite holes can be an effective remedy. Adding salt to any potential termite entrances, such as cracks or holes in foundations or walls, can help keep termites from taking up residence in your home in the first place. You can also use saltwater to kill spiders, and dry salt sprinkled around your house can kill fleas. Epsom salt isn’t the same as table salt, but you can use it in much the same way, at least in terms of pest control.

Epsom salt crystals on a gray table

What does salt do to pests?

Salt kills pests by dehydrating them, and there are two ways it causes dehydration in pests. Pests with exoskeletons, like fleas or beetles, typically die when the coarse edges of salt grains scratch their exoskeleton. When their exoskeletons are scratched, they lose the ability to retain water. Salt, Epsom salt, diatomaceous earth, and even coarse sand can all have the same effect.

The second way salt causes dehydration is through ingestion or absorption. Slugs and snails have thin skin and absorb things through their skin. Even a little bit of salt absorbed through the skin or ingested causes severe dehydration. This is the same process that happens to us when we drink too much seawater, but since insects are so much smaller, it takes a lot less salt to dehydrate them.

Gardener pulling weed
Effective Stock Photos / Shutterstock

Getting rid of weeds

Rising in popularity has been the use of Epsom salt as a weed killer. Recipes call for a mix of dish soap or liquid detergent, Epsom salt, and vinegar. At first glance, the mixture seems to work quite well, with leaves drying and dying rapidly. However, the effects don’t last long, and it’s easy to see why when considering the ingredients.

Epsom salt can harm plants in large doses, but in smaller amounts, it improves a plant’s health. Vinegar is acidic and will dry leaves out when applied directly. However, if the weed’s roots run deep, they won’t be affected by the vinegar and the plant will grow back. Dish soap helps the solution stick to plant leaves but otherwise doesn’t help or harm the plant.

If you have smaller weeds with shallow roots, then a concoction of dish soap and vinegar may be helpful. Just remember that vinegar can also harm any other plants nearby. Don’t add any dish soap or detergent that contains bleach, either. Bleach and vinegar create a potentially lethal chlorine gas when mixed.

A fruit-bearing pomegranate tree
CherryTattka / Shutterstock

More flowers, more fruit

In addition to developing chlorophyll, magnesium helps strengthen your plants, potentially increasing the number and size of the flowers and fruits produced by the plant. If you’re looking to increase your harvest, you may want to target individual plants.

Dilute Epsom salt in water, roughly 2 tablespoons per gallon. You can water your plants with this instead of normal water once a month, or you can fill a spray bottle and gently mist your plants with it. Avoid misting plants that don’t like to get their leaves wet, like succulents, and you should see the benefits when your plants start blooming and producing fruit.

Epsom salt is good for more than just soothing baths: you can use it to strengthen and enhance your plants, increase your yield or blooms, and keep pests out of your garden. Although it doesn’t work as a weed killer, it has plenty of other good gardening uses. Remember not to overuse it — it only takes a little bit to achieve major benefits.

Cayla Leonard
Cayla Leonard is a writer from North Carolina who is passionate about plants.  She enjoys reading and writing fiction and…
How to grow celosia and add vibrant color to your garden
These tips will help you keep your plants healthy
Pale orange celosia flowers

Does your home or garden need a burst of color and texture to liven it up? Celosia is the perfect plant! Celosia flowers come in many shades of orange, red, yellow, and pink. There are two primary shapes they come in -- one that is flame or feather-shaped plant and another that is folded in waves, typically called cock’s comb celosia. Both are beautiful and easy to grow, so why not pick your favorite and get started? Here’s everything you need to know to bring this gorgeous flower to your home or garden.
Planting celosia

Celosia is a tender perennial, meaning it is sensitive to the cold. Only plant it after the last frost of the year has passed, or start it indoors. Choose well-draining soil that's rich in organic matter. Celosia can tolerate most soil types, but mixing compost or leaf mulch into the soil before planting can help improve the drainage and nutritional value, keeping your celosia happy. Potted celosia can be planted in any well-draining potting soil.

Read more
What to know about climate zones before planting your garden
How to use the USDA hardiness zones when gardening
Peach tree

One of the most important aspects of gardening is learning what plants will grow successfully in your region. Climate zones - also referred to as plant hardiness zones or growing zones - provide general guidelines to let gardeners know what plants are hardy in their area. Wondering how these climate zones are divided, why they matter, and how to use that info in your own garden? Then this is the guide for you! We'll walk you through everything you need to know about climate zones for plants, so that you can go into the next gardening season as confident as possible.
What you need to know about climate zones

So, what is a climate zone? In the 1960s, the United States Department of Agriculture divided the country into different regions with the Plant Hardiness Zone Map. The gist is relatively straightforward: Scientists used temperature data to split the country into multiple zones based on average annual minimum temperatures. Each area is separated by a difference of 10 degrees Fahrenheit. And in case you were wondering, yes, an individual state can consist of several zones!

Read more
6 gorgeous mums to add color to your autumn garden 
How to find the perfect mums for your fall garden and properly care for them
A chrysanthemum plant with several round, reddish-pink flowers

Come early fall, you’ll find beautiful mums in virtually every color lining nursery display tables. They come in an array of gorgeous colors, sizes, and shapes, making mums one of the most popular autumn plants for gardens, patios, and homes. From deep oranges to sunny yellows, mums are an excellent way to add some cheer to your garden during a season when many other flowers are beginning to fade.

With so many options, it can be overwhelming to find just the right one for cozying up your garden — even if you're only keeping it for the fall season. If you’re wondering which mum best suits your landscape, keep reading to learn about the different types of autumn garden mums.
Are chrysanthemums and mums the same flower?

Read more