Finding irregular holes and skeletonized leaves on your kale is a common garden complaint with a few likely culprits. If you’re wondering whats eating my kale, you are not alone. This problem plagues gardeners everywhere, from small backyard plots to large urban farms. The good news is that identifying the pest is the first step to reclaiming your greens.
This guide will help you become a garden detective. We will examine the most common insects and animals that target kale. You will learn how to spot the signs they leave behind. We will then provide clear, effective strategies for control and prevention. By the end, you’ll have a plan to protect your kale crop.
Whats Eating My Kale
To solve the mystery, you need to examine the evidence. Different pests leave distinct types of damage on kale leaves. The time of day you see the damage can also be a major clue. Let’s break down the primary suspects by the clues they leave.
Chewing Pests That Leave Holes
These are the most obvious offenders. They take bites right out of the leaves, creating holes of various sizes.
Cabbage Worms And Cabbage Loopers
These are the larval stage of common white butterflies and gray moths. You’ll often see the adult butterflies fluttering around your plants. The damage they cause is significant.
- Signs: Irregular, ragged holes in the middle of leaves. Dark green frass (caterpillar droppings) on and around leaves.
- Identification: Cabbage worms are velvety green. Cabbage loopers are light green and inch along by arching their backs.
- Favorite Target: They prefer the tender, younger leaves in the center of the plant.
Flea Beetles
These are tiny, jumping beetles that can be black, bronze, or striped. They are especially problematic for young seedlings.
- Signs: Dozens of small, shotgun-like holes in leaves. The leaves can look skeletonized if the infestation is severe.
- Identification: The beetles are very small (about 1/16 inch) and will jump like fleas when disturbed.
- Favorite Target: They attack the cotyledons and first true leaves of young plants.
Slugs And Snails
These mollusks feed at night and love moist, cool conditions. They can decimate young kale plants quickly.
- Signs: Large, irregular holes with smooth edges. A telltale silvery slime trail on leaves and soil.
- Identification: Check your plants after dusk with a flashlight to catch them in the act.
- Favorite Target: They go for the lower, older leaves that are closer to the damp soil.
Sucking Pests That Cause Discoloration
These insects pierce plant cells and suck out the sap. They cause damage that is less about holes and more about overall plant health.
Aphids
Tiny, soft-bodied insects that cluster on the undersides of leaves and stems. They come in green, black, or gray.
- Signs: Leaves may curl, pucker, or turn yellow. Sticky “honeydew” residue on leaves, which can lead to sooty mold.
- Identification: Look for dense clusters of small, pear-shaped insects on new growth and leaf undersides.
- Favorite Target: They love the tender new growth at the top of the plant and leaf joints.
Harlequin Bugs
These stink bugs are brightly colored with black and red-orange markings. They are a serious pest in warmer regions.
- Signs: White or light yellow blotches on leaves. Wilting, browning, and plant death if infestation is heavy.
- Identification: The adults are shield-shaped and conspicuously colored. Nymphs are smaller and rounder.
- Favorite Target: They pierce plant tissue and suck out juices, causing widespread damage.
Pests That Skeletonize Leaves
These pests eat the leafy green material but leave the veins intact, creating a lace-like effect.
Imported Cabbageworms
Similar to the standard cabbage worm, but the damage can be more severe, leading to complete skeletonization.
- Signs: Leaves are stripped down to just the veins, creating a transparent “windowpane” effect.
- Identification: The caterpillars are green and may be harder to spot as they blend with leaf veins.
Beet Armyworms And Other Larvae
These caterpillars can feed in groups and rapidly defoliate plants.
- Signs: Rapid removal of leaf tissue between veins, leading to large skeletonized areas.
- Identification: Color can vary from green to brown. Look for groups feeding together.
Larger Animal Pests
Sometimes the culprit isn’t an insect. Mammals and birds can also find kale quite tasty.
- Rabbits: Leave clean-cut, angled bites on leaves and stems, often low to the ground.
- Deer: Cause large, torn sections of leaves and can eat entire plants, leaving ragged stems.
- Groundhogs/Woodchucks: Can eat entire plants down to the ground. Look for burrows nearby.
- Birds: Sparrows or pigeons may peck at leaves, creating small, irregular holes.
How To Identify The Culprit: A Step-By-Step Guide
Follow this simple investigative process to pinpoint exactly what’s damaging your kale.
Step 1: Examine The Damage Closely
Look at the leaves carefully. Take note of the size, shape, and pattern of the holes or marks.
- Are the holes large and ragged or small and shotgun-like?
- Is just the green material gone, leaving veins behind?
- Are the leaves curled, yellowed, or sticky?
Step 2: Check The Undersides Of Leaves
This is where most pests hide during the day. Gently turn leaves over and look for insects, eggs, or larvae.
Step 3: Inspect At Different Times Of Day
Some pests, like slugs and caterpillars, feed more actively in the evening or early morning. Do a flashlight check after dark.
Step 4: Look For Secondary Signs
Search for frass (droppings), slime trails, eggs, or shed insect skins on and around the plant.
Step 5: Monitor The Progression
Check your plants daily. Note if the damage is getting worse quickly or staying localized. This can indicate the pest’s size and appetite.
Organic And Natural Control Methods
Once you’ve identified the pest, you can choose the most effective and environmentally friendly control strategy.
Manual Removal
This is often the most immediate and effective method for larger pests.
- For Caterpillars: Pick them off by hand and drop them into a bucket of soapy water. Check plants daily.
- For Slugs and Snails: Handpick at night. You can also set traps like shallow dishes of beer sunk into the soil.
- For Egg Clusters: Scrape off the yellow egg clusters of cabbage butterflies from leaf undersides.
Barrier Methods
Prevent pests from reaching your plants in the first place.
- Floating Row Covers: Lightweight fabric placed over plants immediately after planting. It blocks butterflies, moths, and beetles. Ensure the edges are sealed to the ground.
- Collars: Make cardboard or aluminum foil collars around seedling stems to deter cutworms and slugs.
- Copper Tape: Apply adhesive copper tape around raised beds or pots; it gives slugs and snails a slight electric shock.
- Fencing: Use chicken wire or hardware cloth to exclude rabbits and groundhogs. For deer, fencing needs to be at least 8 feet tall.
Natural Sprays And Solutions
These target pests without harming beneficial insects or the environment when used correctly.
Insecticidal Soap
Effective against soft-bodied insects like aphids. It works by breaking down their outer coating.
- Purchase a ready-to-use organic insecticidal soap or make a mild solution with pure castile soap.
- Spray directly onto the pests, thoroughly coating the undersides of leaves.
- Apply in the early morning or late evening to avoid harming pollinators. Reapply after rain.
Neem Oil
A versatile organic oil that disrupts the life cycle of many insects. It acts as a repellent, an antifeedant, and a growth regulator.
- Mix according to package directions. Always do a test spray on a few leaves first.
- Spray all plant surfaces, including leaf undersides, until dripping wet.
- Apply every 7-14 days as a preventative or more often for active infestations.
Bacillus Thuringiensis (Bt)
A natural soil bacteria that is toxic only to caterpillars when they ingest it. It is completely safe for humans, pets, and beneficial insects.
- Choose the Bt *kurstaki* strain for cabbage worms and loopers.
- Spray it evenly on leaves. Caterpillars will stop feeding within hours and die in a few days.
- Reapply after rain or every 1-2 weeks as needed.
Diatomaceous Earth (DE)
A fine powder made from fossilized algae. Its sharp edges cut the exoskeletons of crawling insects, causing them to dehydrate.
- Use food-grade DE only.
- Dust a light, visible coating on dry leaves and around the base of plants.
- Reapply after rain or heavy dew, as it loses effectiveness when wet.
Introducing Beneficial Insects
Encourage or purchase insects that are natural predators of kale pests.
- Ladybugs and Lacewings: Their larvae are voracious aphid eaters.
- Parasitic Wasps: Tiny wasps that lay eggs inside caterpillars, controlling their population.
- Attract Them: Plant nectar-rich flowers like dill, cilantro, yarrow, and alyssum near your kale to provide habitat for beneficials.
Cultural Practices For Prevention
A healthy garden ecosystem is your best long-term defense. These practices make your kale less appealing to pests.
Crop Rotation
Never plant kale or other brassicas (cabbage, broccoli, cauliflower) in the same spot two years in a row. This breaks the life cycle of soil-borne pests and diseases.
Companion Planting
Some plants repel pests or attract their predators when planted nearby.
- Strong-Scented Herbs: Plant thyme, dill, mint, rosemary, or sage around kale to confuse and repel pests.
- Alliums: Interplant with onions, garlic, or chives to deter aphids and cabbage worms.
- Nasturtiums: These act as a “trap crop,” attracting aphids and cabbage butterflies away from your kale.
Garden Hygiene
Keep your garden clean to remove pest hiding places and overwintering sites.
- Remove and destroy severely infested plant material immediately. Do not compost it.
- Clear away plant debris and weeds at the end of the season.
- Turn the soil in fall to expose overwintering pupae to birds and cold weather.
Healthy Soil And Proper Watering
Strong plants are more resilient to pest damage.
- Amend soil with compost to provide steady nutrients.
- Water consistently at the base of the plant, avoiding overhead watering which can spread disease and attract slugs.
- Use mulch to conserve moisture and suppress weeds, but keep it a few inches from plant stems to discourage slugs.
When To Use Chemical Controls
Organic methods are prefered and usually sufficient. Synthetic pesticides should be an absolute last resort due to their impact on beneficial insects and the environment.
If you must use them, always choose the least toxic, most targeted option. Read the entire label carefully and follow all instructions for application rates and safety precautions. Never apply pesticides to plants in flower, as they will harm pollinators.
Frequently Asked Questions
What Is Making Holes In My Kale Leaves?
The most common causes of holes in kale leaves are cabbage worms, cabbage loopers, flea beetles, and slugs. Identifying the size and pattern of the holes will help you determine which pest is responsible.
How Do I Keep Bugs From Eating My Kale Naturally?
You can protect your kale naturally by using floating row covers as a barrier, applying organic sprays like neem oil or Bt, encouraging beneficial insects, and practicing companion planting with strong-scented herbs.
What Can I Spray On Kale For Bugs?
Effective organic sprays include insecticidal soap for aphids, neem oil for a broad range of pests, and Bacillus thuringiensis (Bt) specifically for caterpillars. Always spray in the early morning or late evening.
Do Coffee Grounds Deter Pests On Kale?
While sometimes recommended, coffee grounds are not a reliable pest deterrent for kale. They may slightly repel slugs due to texture, but they are better used as a soil amendment for acidity-loving plants. Focus on proven methods like row covers and manual removal.
Why Are My Kale Leaves Turning Yellow With Holes?
Yellowing leaves with holes often indicate a combined problem. The holes are from chewing insects like worms or beetles. The yellowing could be from stress caused by the damage, or it could be a separate issue like a nutrient deficiency, overwatering, or a disease like fusarium wilt. Inspect the plant closely for pests and review your watering and fertilization practices.