To stop bugs from eating your cabbage plants immediately, treat your cabbage with natural products such as Bt bacterium, neem oil, and set out beer traps for snails. You can also use commercial insecticides to wipe out cabbage pests or pick the worms off by hand. In order to prevent insects from preying upon cabbage, use row covers to protect the plants from flying insects. You can also grow companion plants near your cabbage that naturally deter insects.
What Types of Bugs Eat Cabbage Plants?
Of the several species of insects that eat cabbage, the most common are cabbage worms and cabbage loopers. These small green, brown, or yellow worms are actually the caterpillars of moths and butterflies. While the adults of these species are usually harmless to cabbage, the young will eat the outer leaves of the plants.
- Most cabbage-eating worms are actually butterfly and moth caterpillars.
- Beware of white butterflies—their caterpillars often eat cabbage.
- Aphids are common cabbage pests.
- Snails and slugs may attack your cabbage.
Aphids and flea beetles are two common insect pests that feed on cabbage leaves. If you find flat green or brown insects on the undersides of leaves, you have an aphid infestation. Flea beetles are recognizable because these small black beetles jump when startled. Common garden slugs and snails will also eat your cabbage leaves, especially at night.
7 Methods to Stop Bugs From Eating Your Cabbage Plants
Because so many garden pests are after your cabbage, you need to use the right methods to stop them. Below is a list of tactics, with specific notes on what cabbage-eating pests each one stops. Using this list, you can keep your cabbage harvest safe.
Bt Powder
Bt powder, short for Bacillus Thuringiensis, contains a natural bacteria that kills pest moth and butterfly larvae. This product is not a pesticide. It is a naturally occurring bacteria that kills cutworms and other larvae. As the worms try to eat your cabbage, they will be killed off by the bacteria.
- Use this Bt powder to protect cabbage from a cabbage looper, cutworm, or other caterpillars.
- Bt powder contains a non-chemical bacteria that kills off harmful worms and caterpillars.
- Dust the powder onto the cabbage head once every 1–2 weeks to kill off worms.
To use Bt powder, dust it on your cabbage leaves every 1–2 weeks. It will keep the worms and all types of green caterpillars from eating your leaves. As a bonus, Bt powder won’t introduce any chemicals into your garden.
Best For: Stopping infestations of cutworm, cabbage looper, and any other small green, yellow or brown worms on your cabbage.
Neem Oil
Neem oil is another natural option for killing off harmful insects. While it won’t work on worms, neem oil will kill and repel flea beetles and aphids. Because it is a natural oil derived from a tree, neem oil is environmentally safe and not harmful to humans or other plants.
- Neem oil is a natural tree oil that will kill aphids and flea beetles.
- Mix 1 tablespoon of this neem oil with 3–4 cups of water and 1 teaspoon of dish soap.
- Spray pest insects on plants thoroughly to kill them.
To use neem oil to treat your cabbage, mix 3–4 cups of water with 1 tablespoon of neem oil and 1 teaspoon of dish soap. Mix thoroughly, then spray your cabbage leaves with the mixture. This mixture is especially potent against aphids. If you spray it on clusters of aphids on the bottom of your cabbage leaves, you’ll kill off the culprits quickly.
Best For: Non-worm cabbage pests, such as aphids and flea beetles.
Beer Lures
If you have slugs and snails infesting your garden, kill them off with beer. No, really. Pour beer into shallow bowls or Tupperware containers and arrange them near your cabbage. Rather than go for the plants, snails and slugs will be drawn to the beer. Once they enter the bowl, they’ll drown.
- Pour beer into several small bowls or plastic containers.
- Arrange the beer lures near your cabbage.
- Snails and slugs will be attracted to the beer and drown in it, leaving your cabbage unharmed.
- Beer is a much better slug-killing option than salt.
Beer is a safer way to stop snails and slugs than using rings of salt to protect your cabbage plants. Salt will leach into the ground and increase the salinity of the soil. This can kill your cabbage plants or any other plant that attempts to grow in your garden in the future.
Best For: Eliminating slugs and snails.
Insecticidal Soap
If natural methods aren’t cutting it and infectious aphids and other leaf-devourers won’t leave your cabbage alone, use a garden-safe insecticidal soap. These products can be safely used on vegetables and fruits without harm to humans, but they’ll wipe out pest insects.
- This insecticidal soap will kill off cabbage-eating insects but is safe for use on edible plants.
- Insecticidal soap is effective at killing aphids and flea beetles but does not kill worms, slugs, and caterpillars.
Always follow the instructions on the bottle when using an insecticidal soap. Most products only need to be sprayed once every 1–2 weeks to kill off infestations. Once you pick your cabbage leaves, just be sure to wash them thoroughly before eating.
Best For: Aphids, flea beetles, and similar insects. Not effective against cutworms and caterpillars.
Pick Off the Worms
One way to deal with worms that infest your cabbage is to simply pick them off by hand and kill them. If you have the time to go out into your garden on a daily basis and inspect your cabbage plants, this method can be just as effective as applying Bt bacterium.
- Pick or knock green cabbage worms and similar pests off your cabbage leaves.
- Crush or otherwise kill the worms to stop the infestation.
This method works best for small plots and backyard gardens. If you’ve been battling holes in cabbage leaves and your schedule doesn’t allow you to tend to your garden daily, Bt powder is a stronger option.
Best For: Killing cutworms, cabbage loopers, and other caterpillars.
Use Row Covers
Because so many cabbage pests are larvae of flying insects, one of the best ways to protect your plants from being eaten in the first place is to cover the plants with an insect-proof row cover. This will stop species of cabbage moth and white butterflies from laying eggs on your cabbage. Your cabbage patch will be totally worm-free.
- These row covers can be laid over your cabbage plants to stop worms and caterpillars.
- Row covers prevent insects from laying eggs on your cabbage
- Row covers allow your crop to receive water, air, and sunlight.
Because row covers allow water and sunlight to reach your plants, you don’t have to worry about smothering your cabbage. Keep in mind, row covers are a preventative measure that won’t kill off existing worms, but they will prevent more from arriving.
Best For: Preventing worms and caterpillars from eating your cabbage.
Grow Companion Plants
Did you know that several common varieties of plants drive off pest insects? The scent of garlic, peppermint, sage, thyme, and rosemary are all known to drive away butterflies, moths, and other cabbage pests. So, it may be a good idea to plant rows of these herbs on either side of your cabbage.
- The scents of certain plants ward off cabbage-eating insects.
- Plant companion crops near your cabbage to keep moths, butterflies, and other insects away from your cabbage.
- Some good companions for cabbage are garlic, rosemary, thyme, sage, and peppermint.
Choose a companion plant that you enjoy cooking with. Garlic is a staple of many cuisines, while peppermint is so useful it may even repel rodents from your garden. Each of these plants can provide its own benefit to your table in addition to warding off cabbage pests.
Best For: Preventing infestation when planting your garden in spring.
Methods to Avoid When Protecting Cabbage
Despite what some online guides recommend, you should never spray a mixture containing vegetable oil on your cabbage plants in order to kill bugs. The viscous oil will prevent the plant from respiration, interrupting photosynthesis and killing your plant. You might kill a few insects, but you’re sure to destroy your year’s cabbage crop in the process.
- Vegetable oil mixes
- Salt
- Strong Pesticides
Similarly, do not use salt in your garden as a slug and snail stopper. Salt will wash into the soil and can be carried long distances by water. Most garden plants can’t tolerate salt in the soil. By spreading salt, you may turn your garden into a dead zone. As a precaution, avoid any strong pesticides that are not specifically advertised as being safe for use on fruits and vegetables.
How Do You Stop Your Cabbages From Being Eaten by Bugs?
If you want to stop malicious insects from eating your cabbage you should:
- Use Bt powder to naturally kill off worms and caterpillars.
- Spray a natural neem oil mixture to wipe out aphids and flea beetles.
- Place beer traps to drown slugs and snails.
- Try a produce-safe pesticidal soap if aphids and beetles keep returning.
- Pick off worms by hand to protect your plants.
- Protect your cabbage with row covers to stop moths and butterflies from laying eggs on them.
- Plant insect-deterring companion plants (like garlic and peppermint) near your cabbage.
Each of these methods is an excellent pest killer or deterrent. By using one or more of these methods, you can wipe out whatever’s eating your cabbage and prevent a return of the pests.