This $20 Organic Fix Could Be the Secret to Pest-Free Tomato Plants This Season
Don't let pests ruin your tomatoes. This affordable, natural product can help you banish pests from your tomato plants this summer.
Amy Draiss
Sign up for the Gardening Know How newsletter today and receive a free copy of our e-book "How to Grow Delicious Tomatoes".
You are now subscribed
Your newsletter sign-up was successful
Nothing says summer like a nice, juicy tomato, but pests can ruin all the tasty fun. Your crop of delicious tomatoes can perish from pest infestations if not treated quickly and efficiently.
You don’t have to let tomato plant pests destroy your harvest. Take control with the help of an organic, non-chemical pest solution: diatomaceous earth. Diatomaceous earth (DE) is a physical method of insect control that is cheap and incredibly effective. A little sprinkle of DE when pests pop up will keep your tomatoes from becoming a bug buffet. You can find food-grade diatomaceous earth on Amazon or your local garden center.
Let’s dig in and explore how to use diatomaceous earth to control insects on your tomato plants.
Common Tomato Pests
First, we need to explore what types of pests are most likely to affect your tomato harvest. Common tomato plant pests include: aphids, cutworms, hornworms, flea beetles, and root-knot nematodes. These pests can wreak havoc on your tomato plants and it is best practice to inspect your plants every day so you can jump on any infestations that may pop up.
Grab a cup of coffee in the morning and go check on your plants as you get your day started! Keeping on top of pest problems is important to the survival of your plants.
In addition to daily monitoring, a sprinkle of diatomaceous earth around the base of your plants can help keep pest problems from cropping up. Pests like root-knot nematodes and cutworms are at the soil level and can be stopped before they even get started.
What is Diatomaceous Earth?
Diatomaceous earth, or DE, is a powder made from fossilized microscopic sea creatures called diatoms. DE is a physical pest control method. All the tiny fossils in the powder are jagged and scratch the bodies of insects as they crawl over it. This causes the insects to dry out and die. It works on common tomato pests, slugs, snails, and any other insect with an exoskeleton. It is a very effective method of pest control, but it needs to be used wisely.
Sign up for the Gardening Know How newsletter today and receive a free copy of our e-book "How to Grow Delicious Tomatoes".
DE doesn’t discriminate between pests and beneficial insects. You don’t want to hurt bees, butterflies, moths, and other beneficial pollinators so you should use DE sparingly. As a general rule, don’t use DE on the leaves or upper stems of plants when they are in bloom. If bees and flies come into contact with it while they are pollinating your plants, they will die.
It is important that you purchase “food-grade” DE so that it is safe to use on plants you are going to eat.
How to Use DE
Before you use diatomaceous earth in your garden, you do need to take some safety precautions. DE is not toxic to humans or pets, but the tiny fossils that scratch up bug bodies can also irritate our eyes, noses, and lungs. It is important to use a mask, goggles, and gloves when handling DE so you don’t develop any irritation.
Sprinkle DE around the base of your tomato plants to prevent insects from crawling along the ground and up tomato stems. Nematodes and cutworms won’t stand a chance.
If you have aphids or flea beetles, use a puffer to delicately coat leaves that have an active infestation. Again, don’t use DE when your tomato plants are in bloom or you risk killing your pollinators. Reapply after rain.
Now, that you have your tomato pests under control, you can put the DE away until you need it again. It is a remarkably effective pest solution and easy on the wallet. Sit back and enjoy those wonderful tomatoes!
Shop Tomato Goodies
This vase measures 10.5 inches high and will bring an extreme pop of color to whatever room it lives in.
This 16-oz Dutch oven from Staub is a gorgeous addition to your kitchen. (I have two Staubs – they're amazing!)
Welcome summer into your home with this cheerful tomato doormat that is almost too cute to walk on!
Looking for additional tips on growing perfect tomatoes? Download our FREE Tomato Growing Guide and learn how to grow delicious tomatoes.

Kathleen Walters joined Gardening Know How as a Content Editor in 2024, but she grew up helping her mom in the garden. She holds a bachelor’s degree in History from Miami University and a master’s degree in Public History from Wright State University. Before this, Kathleen worked for almost a decade as a Park Ranger with the National Park Service in Dayton, Ohio. The Huffman Prairie is one of her favorite places to explore native plants and get inspired. She has been working to turn her front yard into a pollinator garden.
- Amy DraissDigital Community Manager