If you are a fan of growing kale, you are probably aware of the numerous health benefits this leafy green veggie offers and how easy it is to grow this versatile crop. However, when growing your veggies, you also need to face its pests and diseases. Then it is only logical to learn about them and how to fight them. And that’s exactly what we’ll be covering today, how to control kale pests.
Kale is a cabbage relative that is classified as Brassica oleracea. Considered a powerhouse of nutrients, kale is usually grouped in the cooking greens category, so it certainly has a place in a healthy diet.
Kale has a relatively fast growth rate and can grow from seed to harvest in a few weeks. It is a biennial plant that is typically grown as an annual. It is best to direct sown or transplanted in the late winter/early spring in cooler climates, and late summer in warmer climates, for fall-winter harvesting.
Types of Kale Pests
When grown conventionally, this member of the cabbage family is notorious for rot diseases and attracting insect pests. It is susceptible to black rot and clubroot and aphids, cabbage loopers, cabbageworm, cutworms, flea beetles, and slugs. Let’s learn about the most common pests.
These are a common pest, also known as imported cabbageworms and the Latin name is Pieris rapae, or Artogeia rapae.
Cabbageworms affect other members of the cabbage vegetable family like cauliflower, broccoli.
These are esy to spot as you will see a velvety green larvae, and if you see a hole in a leaf; it is also a sing of Cabbageworms. These will eventually become white butterflies, which are mostly white with a few black markings.
Cabbage worms can happily eat away leaves however plants can withstand much leaf loss without consequence. During seedling establishment or early head formation, plants will incur true damage to their growth and yield.
How to get rid of cabbage worms
There are a few things you can try to control cabbage worms:
- Manually remove (handpick) the eggs if possible.
- Yellow sticky traps will catch the adult butterflies, but may also catch beneficial insects.
- Spraying with Bacillus thuringiensis var. kurstaki every 1 to 2 weeks will also help control cabbage family pests. Sevin also is effective. If you dampen cabbage leaves and sprinkle them with cornmeal, the caterpillars will eat the meal, swell, and die.
- Check with your local Cooperative Extension for your area’s regulations on chemical control.
Avoid cabbage worms
- Cover your plants with row covers to deter the adult butterflies from laying eggs on the cabbages.
- Trichogramma wasps (very tiny; they do not sting humans) parasitize the eggs of the imported cabbageworm; these beneficial insects are available by mail order.
- Companion planting is a useful deterrent for many pests. Cabbage worms are repelled by thyme, so it would be a good idea to plant thyme near.
- Try planting red-leafed varieties of cabbage. The cabbage worms won’t be able to camouflage, so they are less likely to choose these plants.
Kale Pests: Flea beetles
Everyone has faced flea beetles in their garden at least once. Flea beetles are small, shiny-coated beetles with large rear legs. They get their name because they jump like fleas when threatened.
There are many species of flea beetles. Some species attack a wide range of plants, while others target only certain plant families. Kale and those in the Brassica family are especially susceptible to these pests.
You will know your kale crop has flea beetles early in the planting phase which is when they are most susceptible to beetle damage. Eggs are laid at the base of plant stems in early summer after the spring feeding period, and larvae feed at the roots.
Adult beetles will make their territory with shotholes in the leaves, especially on young seedlings. The holes can quickly damage the leafy greens. However, the real danger is that the beetles can spread bacterial diseases, such as wilt and blight, from plant to plant.
How to get rid of flea beetles
- Homemade spray recipe: 2 cups rubbing alcohol, 5 cups water, and 1 tablespoon liquid soap. Test out the mixture on a leaf of the plant, let it sit overnight, then spray the rest of the plant if you don’t notice any adverse effects.
- Use white sticky traps to capture flea beetles as they jump.
- Insecticides may be used early in the season, otherwise, they won’t be of much help on adult plants.
Avoid flea beetles
- In the spring, emerging flea beetles will be waiting to feast on your garden. Cut off their food supply by delaying transplanting or planting by a couple of weeks if possible.
- Immediately after transplanting employ row covers as these may be successful at keeping these pests out.
- Flea beetles are repelled by catnip and basil. They are attracted by nasturtium and radishes. You can plant these as traps for the flea beetles so that they do not attack other more valuable plants.
Those little green bugs on your kale are most likely Cabbage Aphids, you’ll find these tiny bugs clustered between the leaves.
These soft-bodied insects feed by sucking the nutrient-rich liquids out of plants. In large numbers, they can weaken plants significantly. Aphids multiply quickly, so it’s important to get them under control before reproduction starts.
Aphids species can appear in different colors and they have bodies with long antennae. Adult Aphids will target leaves, stems, buds, flowers, fruit, and/or roots, depending on the species. Most aphids especially like succulent new growth. Aphids may transmit viruses between plants and attract other insects that prey on them, such as ladybugs.
How to get rid of Cabbage Aphis
- These are easily solved with a spray of insecticidal soap. You could also try spraying cold water on the leaves; sometimes, they need a cool blast to remove them.
- If you are dealing with an Aphids invasion, do not panic, dust plants with flour. It constipates the pests.
- You can often get rid of aphids by wiping or spraying the leaves of the plant with a mild solution of water and a few drops of dish soap. Soapy water should be reapplied every 2-3 days for 2 weeks. Neem oil, insecticidal soaps, and horticultural oils are effective against aphids.
Avoid Cabbage Aphids
- Companion planting can be very helpful to keep aphids away from your plants in the first place. Aphids are especially attracted to mustard and nasturtium. Plant these near more valuable plants as traps for the aphids.
- For fruit or shade trees, spray dormant horticultural oil to kill overwintering aphid eggs.
- Beneficial insects, such as ladybugs, lacewings, and parasitic wasps, will feed on aphids.