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Holes in brussel sprout leaves are usually caused by pests, and figuring out which one is behind the damage is the first step to fixing it.
If you’ve been wondering why your brussel sprout leaves have holes, you’re definitely not alone.
It’s one of the most common complaints among gardeners growing this crop.
In this post, we’ll look at why brussel sprout leaves have holes, how to spot the culprits, and what you can do to protect your plants going forward.
Let’s dig in.
Why Brussel Sprout Leaves Have Holes
Brussel sprout leaves have holes because something is eating them, and in most cases, it’s one of a handful of common garden pests.
Here are the main reasons your brussel sprout leaves have holes:
1. Cabbage Worms and Caterpillars
Cabbage worms are the number one reason brussel sprout leaves have holes.
These green caterpillars come from eggs laid by small white butterflies that flutter around your garden in summer.
The larvae chew irregular holes through the leaves and can strip a young plant fast if you don’t catch them early.
Check the undersides of leaves for tiny green worms or clusters of yellow eggs.
2. Flea Beetles
Flea beetles are another common cause of holes in brussel sprout leaves.
They’re tiny, dark, jumping insects that leave a pattern of small “shot holes” across the foliage.
The damage looks like someone peppered your leaves with a hole punch.
Flea beetles are especially active in spring, when seedlings are most vulnerable.
3. Slugs and Snails
Slugs and snails can also leave brussel sprout leaves with holes.
Their damage tends to be larger and more ragged than beetle holes, often appearing overnight.
If you notice slimy trails or silvery patches near the damage, slugs are likely the culprits.
They come out in damp weather and feed mostly after dark, so you might not catch them in the act.
4. Cutworms
Cutworms chew holes in brussel sprout leaves, especially on younger plants close to the soil line.
These caterpillars hide in the soil during the day and feed at night.
If your brussel sprout leaves have holes near the bottom of the plant, cutworms deserve a spot on your suspect list.
5. Cabbage Loopers
Cabbage loopers are another caterpillar pest behind holes in brussel sprout leaves.
They move with a distinctive looping motion and chew large, ragged holes between the leaf veins.
Like cabbage worms, they’re the offspring of moths and butterflies that target brassicas.
A single looper can do surprising damage in just a few days.
How to Stop Holes in Brussel Sprout Leaves
Now that you know why your brussel sprout leaves have holes, let’s talk about putting a stop to it.
The good news is that you don’t need harsh chemicals to protect your crop.
1. Inspect Your Plants Regularly
The simplest defense against brussel sprout leaves with holes is a weekly inspection.
Flip over leaves, look for eggs, and pick off caterpillars by hand.
Catching pests early means your brussel sprout leaves stay intact instead of turning into Swiss cheese.
2. Use Row Covers
Floating row covers are a fantastic barrier against the pests that cause brussel sprout leaves with holes.
Drape them over your plants before butterflies and beetles show up.
Just remember to lift the covers once your plants start forming sprouts so pollinators and airflow can do their thing.
3. Encourage Beneficial Insects
Planting flowers like marigolds, dill, and calendula brings in ladybugs and parasitic wasps that prey on the pests chewing holes in brussel sprout leaves.
It’s a natural way to keep the damage in check without spraying anything.
4. Try Neem Oil or Insecticidal Soap
If brussel sprout leaves have holes and the pests are spreading, neem oil or insecticidal soap can help.
Spray in the evening to avoid harming beneficial insects, and coat the undersides of leaves where the culprits hide.
Repeat every week or so until the holes in your brussel sprout leaves stop appearing.
5. Keep the Garden Clean
Pests overwinter in plant debris, so clear out old brassica leaves at the end of the season.
Rotating your crops also stops the pests that leave brussel sprout leaves with holes from building up in the same spot year after year.
A little tidiness goes a long way.
Do Holes in Brussel Sprout Leaves Mean the Plant Is Doomed?
Not at all, so don’t panic yet.
Brussel sprouts are tough plants, and a few holes in the outer leaves usually won’t affect your harvest.
The sprouts themselves are what you’re after, and they’re tucked away and protected.
What matters is catching the problem before the damage spreads to new growth.
Once you’ve identified why brussel sprout leaves have holes in your garden and taken a few simple steps, your plants will bounce back just fine.
So, Why Do My Brussel Sprout Leaves Have Holes?
Brussel sprout leaves have holes because pests like cabbage worms, flea beetles, slugs, and caterpillars are feeding on them.
The damage looks alarming, but it rarely spells disaster for your crop.
Identify the culprit, take action early, and keep an eye on your plants throughout the season.
Hope this post has helped you understand why brussel sprout leaves have holes and how to keep them from coming back.