After emerging from their eggs, cabbage worms instantly start eating their way through foliage plants.
They’ll go after leafy green crops like broccoli, kale, cauliflower, lettuce, and brussel sprout, as well as cabbages. As a result, it is vital that you get rid of them before an infestation begins.
Chemical sprays may tackle the problem, but for the organic gardener, there are home remedies and other effective eco-friendly options.
Cabbage worms are the larvae form or caterpillars of the small cabbage white butterfly (Pieris rapae) .
Most people enjoy the sight of butterflies flitting about prettily in a sunny garden or delicate moths circling evening lights. The white or black-tipped pale butterflies are particularly delightful to some gardeners.
However, they spell danger to vegetable crops and are not so welcome. These insects may not cause much trouble. However, their larval phase can be very destructive, creating many holes in cabbage leaves and other vegetables.
The larvae, otherwise called cabbage maggots, are hairy velvety green garden worms. You’ll also see signs of their dark green, round poop nearby.
How to Get Rid of Cabbage Worms Naturally
Below are some natural and organic methods and home remedies to kill or control them.
1. Manual Removal
A cost-effective way to eliminate these destructive crop pests is to pick off the eggs and worms with your hands and dispose of them. To do this, it is necessary to identify them correctly to avoid destroying beneficial insects.
You’ll find quite a few types of caterpillars on cabbage, one of which is the cabbage looper, so named for its body-looping movement.
You can identify the diamond-backed and zebra caterpillars by the markings. Besides, they and develop into moths if left undisturbed.
Cabbage whites are familiar woolly green caterpillars. Zebras have black and white markings and the diamond moth worm sports black and white dots on green.
Adults lay eggs singly spaced in tiny yellow or white dots on plant leaves. However, these should not be confused with similar clusters of eggs that indicate the beneficial ladybug is around.
For the squeamish, you can use wads of kitchen towel to pick or rub off the eggs and squish between the sheets before disposal.
2. Floating Row Covers
Covers work by merely blocking out pests and protecting young plants from frosts, wind, and domestic pets.
A white gauze-like material, usually polyester or polypropylene, is what makes this type of cover. Therefore, it allows light, air, and water to filter through.
Hold row covers in place on hoops over raised beds or single rows of vegetables. Moreover, you can remove them when plants are stronger and more pest-resistant.
3. Companion Planting
Growing plants close by that deter cabbage bugs is another organic method of control. Herbs are particularly useful, including thyme, sage, tansy, mint, oregano, and rosemary.
Marigolds are known for deterring a wide range of pests and are attractive too in the vegetable patch. This should also help prevent butterflies from using the cabbage leaves and other greens to deposit their eggs.
4. Beneficial Insects
This is one of the most common, yet natural approaches to ridding the garden of pests.
- The ladybug is so good at feeding on the cabbage pests that you can purchase them from specialist breeders to help populate the garden.
- Lacewings and damsel bugs are other useful insects.
- Parasitic Trichogramma wasps lay their eggs inside the caterpillar or pupae, where they hatch out, feed on, and destroy the host.
Planting attractive flowers like marigolds may encourage all these helpful creatures.
5. Bacillus Thuringiensis (BT) Spray
This is a type of bacteria naturally occurring in the soil that can eliminate cabbage moth caterpillars and similar pests. However, BT is non-toxic to humans, pets, and wildlife and ineffective against useful insects.
One of the most widely used ingredients in commercial organic pesticides, you can purchase it ready for use or as a solution to be diluted.
Mix Bt thoroughly and spray following the instructions on the package, especially after rain.
This cabbage worm killer works by preventing them from feeding and is most successful against younger, tiny green worms.
6. Neem Oil Spray
This is another naturally-occurring insecticide processed from the seeds and fruit of the Neem tree. Like BT, it inhibits the feeding action of those small green worms on plants; thus, disrupting their life cycle.
You can use neem oil effectively as a spray, but it leaves a residue, so it does not need frequent applications. Neem is often used in commercial products combined with other organic pesticides.
For a DIY recipe, combine one tablespoon of neem oil with one tablespoon of organic liquid soap in a gallon of water.
Pour the solution into a spray container and coat your plants.
Apply this simple home remedy by dusting the cornmeal onto plants where the caterpillars can feed on it. The effect will be to make them gradually swell up and die.
Another way if you keep chickens, ducks or geese is to allow them to work for you. These creatures will naturally enjoy picking off the worms and making a meal of them.
9. Sticky Traps
As pretty as the white butterflies are, they are probably shedding their eggs there if they are fluttering about the vegetable patch.
Sticky traps can catch them but may trap helpful pollinators too.
10. Diatomaceous Earth (DE)
This is an old well-tried and tested natural pesticide. Purchase the white powder and puff it directly onto cabbage caterpillars, on and under leaves, and around plants.
DE is a silicon-based type of soil produced from tiny fossilized marine creatures. The powder acts to pierce and dehydrate the larvae and adult caterpillars, eventually killing them.
You can also concoct a spray out of diatomaceous earth by mixing half a cup in a gallon of water.
11. Soap and Water
A simple inexpensive homemade solution of soap and water. Some people use regular dish soap but we recommend using organic liquid soap.
Combine 4 tablespoons of soap in one gallon of water to create a spray solution. Spray on, around, and under plants at all stages in their life cycle.
Mixed with neem oil, this soapy water solution is even more effective.
12. Spinosad Spray
You can buy this pesticide as a ready-prepared spray, sometimes combined with other organic ingredients.
Spinosad is a naturally occurring soil bacteria that become active through a process of fermentation. Moreover, it has a toxic effect on worms and a host of other pests.
13. Beneficial Nematodes
Also occurring naturally in the soil, these microscopic roundworms have a parasitic action on all stages of the life cycle of cabbage worms and other insects.
They release bacteria into the pests destroying them but are non-toxic to birds, fish, wildlife, and pets. Purchase beneficial nematodes from reputable online farm stores.
For the organic gardener, many insect pests like cabbage worms can be controlled by natural methods. With today’s global concern on environmental issues, these ways are proving increasingly popular.