The cabbage moths are a common pests of brassicas, including cabbage, kale, and broccoli. It can also attack other crops such as cauliflower and Brussels sprouts. Here’s how to protect your vegetables and get rid of cabbage moths naturally. You can also apply these guides for controlling cabbage worms, white butterflies, loopers, and other cabbage pests.

What are Cabbage Moths?

The cabbage moths, Mamestra brassicae and Plutella xylostella Diamondback moth, are insects found in Asia, Europe, North America, and South America and affect brassica family vegetables. The adult moth is brownish gray with brownish-yellow hues on the wings. It is about 9 mm long and is easily visible around the cabbage. Its wingspan is about 15 millimeters, which allows it to fly long distances in search of food and a place to lay eggs.

The female lays tiny oval eggs (2-4 pieces) along the main nerve on the reverse leaf. They are yellow but green over time. During her lifetime, each female lays about 300 eggs. After 14 days, caterpillars (larvae) of a characteristic green color hatch from the egg with a slightly darker head. Cabbage worms or caterpillars can reach up to 12mm and are active throughout the day. The larvae transform into pupae after two weeks and 14 days later into an adult (imago).

diamondback moth on cabbage leaf

What Does Cabbage Moth Eat?

The larvae of the cabbage moth may feed on brassica vegetables. They feed on the underside of the leaves of cabbage, kale, and other brassicas. In the beginning, larvae are located inside the epidermis or leaf skin, making mines. After 2-3 days, they feed on the surface of the lower side of the leaf. They are biting it in the form of smaller or larger holes until the destruction of the leaf epidermis so that only the central nerve of the leaves remains.

The cabbage moth butterfly itself is not considered a pest in the vegetable garden. However, the larvae worms will damage the plant if they feed on the leaves’ undersides.

cabbage moth damage on broccoli leaves

When do Cabbage Moths Appear, and Where do They Live?

Cabbage moth overwinters in the pupae stage in various places, trees, shrubs, and weeds, especially in last year’s plots with cabbages. The first butterflies appear at the end of April.

The cabbage moths develops 5-7 generations per year and in favorable conditions even more. This insect is present in the entire vegetation of the cultivated culture. Dry periods with high temperatures are conducive to a more mass appearance and a more significant number of generations.

They can be found in gardens, fields, orchards, and even ornamental plants. There are lots of cabbage moths around in the fall, when they will deposit eggs on your plants.

cabbage moth eggs on underside of leaf

Tips to Prevent Cabbage Pests

Getting rid of the invasion of cabbage pests like moths, caterpillars, worms, loopers, and white butterflies can be a challenging job. Therefore, the most suitable way to deal with pests is prevention. While it may not provide 100% protection, it will at least reduce the number of greedy garden insects.

There are some methods you can use for cabbage pests prevention.

  • Remove abundant grass around the garden’s perimeter, a breeding ground for these pests.
  • Ducks, chickens, and guinea fowl will eat worms and larvae, so don’t hesitate to release them into your vegetable garden.
  • Attract birds, wasps, and other beneficial insects and predators
  • Regularly check foliage and remove eggs and caterpillars from your plants.
  • Pay attention to the crop rotation. Avoid planting brassicas in the same area every year.
  • Do not forget to plow and destroy crop remains and weeds around garden beds because They are a favorite wintering ground for moth and cabbage butterfly pupae.
  • Use garden nettings or row covers to protect your vegetables from pests flying around and laying eggs on your veggies.
row covers deter moths butterflies

What Deters Cabbage Moths?

  • Neem oil will deter cabbage moths, and they tend to leave the oil on the leaves so that you can use it as a foliar spray. It is an excellent insecticide for garden beds where the larvae are feeding. Neem can be used in many ways, like spraying on the plants, mixing it with other insecticides, and making your spray. 
  • White cabbage moth decoys can help you reduce the damage of this destructive pest. The cabbage butterfly and moths will not bother your brassicas if you leave these decoys in place, as they will move on to more lucrative prey. As they are territorial insects, they won’t land to lay their eggs on an already occupied plant when they see fake moths. Butterfly decoys are relatively inexpensive, can easily be set up, and provide adequate protection from moths and butterflies. 
  • Row covers and gardening nets will deter moths and animals like rabbits, birds, and deers. Keep in mind that you might want to consider the fact that there are many different pests and other animals that can be a problem. For instance, if your garden is not protected with a cover, you could have squirrels, raccoons, opossums, and even rats eating from your garden. 
white cabbage butterfly
White cabbage butterfly

Make Your Own Homemade Spray

You can prepare your own natural cabbage moth spray with ingredients found in your home. There is no need to buy a chemical spray that is toxic and dangerous for children, pets, and the environment. 

Garlic Spray

Many pests hate garlic with its intense smell, and you can make your garlic concentrate liquid to use when needed. Squeeze four garlic cloves and add four tablespoons of paraffin mineral oil to create one. After 24 hours, strain and pour into a half-gallon of water, then add two tablespoons of dish detergent. Now you will have potent concentrate, which you can store in a cool and dark place. When you need to spray, the plants take three tablespoons of this liquid and mix it with half a gallon of water.

You can also add four tablespoons of hot pepper to this mixture. This research proved that the efficiency of the combination of garlic and hot pepper is similar to or equal to commercial pesticides for controlling cabbage moths and other cabbage pests.

Essential Oils Liquid

Essential homemade cabbage moth spray will act more as insecticide and repellent at the same time. To make one, you can use many essential oils like neem oil, rosemary, lavender, orange, clove, etc. To prepare one, add one tablespoon of liquid soap in a gallon of water, then slowly add o.3 us oz of desired essential oil. Spray the plants with this liquid when it’s cooled, best in the morning or evening once every 20 days.

cabbage moth caterpillars eating leaf

What Will Kill Cabbage Worms?

In large fields, Cabbage worms larvae are controlled by the use of Bt (Bacillus thuringiensis). Bt is a naturally occurring bacterium that is found in soil. When ingested, Bt produces toxins that kill specific pests. Bt has been used in agriculture for over 50 years. It is safe for people, livestock, fish, and birds. When sprayed on foliage, the bacteria are eaten by the caterpillar, which eventually dies from the toxin.

According to the University of Minnesota natural pesticides can also effectively kill worms from your cabbage. 

  • Pyrethrins are effective natural insecticide that is derived from a chrysanthemum flower. It kills insects within 10 minutes after contact. They should be sprayed directly on the plants or animals and are not intended for human use.
  • Spinosad is a naturally occurring soil bacterium that works as an effective pesticide for many other pests. It is used for killing adult insects and larvae. 

Be careful not to use insecticides just before and during the flowering period; this way you will protect bees and other pollinators.

cabbageworm eggs found on cabbage

Conclusion

There are many ways to prevent cabbage moths from infesting your brassica crops. You can use many natural methods to control cabbage moths, worms, loopers, and butterflies, such as using organic insecticides, cover protection, or deterring them with repellents. There are various methods to prevent cabbage pests from infesting your garden. These also include growing cabbage varieties that are less susceptible to problems, like the red variety, which is less attractive to moths. Or planting companion vegetables like garlic and onions, herbs like dill, thyme, rosemary, and lavender will also repeal many brassica pests.

Don’t forget to care for beneficial insects and moth predators like birds, wasps, and bats, as they are nature’s best pest control method.