There are few things as high on the “ick factor” as finding bugs in broccoli when you’re about to take a bite. Unfortunately, there are many pests that enjoy broccoli plants even more than people do and finding them hidden inside the broccoli florets or munching on the leaves isn’t unusual. In this article, I’ll discuss some of the most common bugs that feed on broccoli and offer strategies for keeping them at bay.
Why finding bugs in broccoli plants is a problem
Aside from grossing you out, bugs in broccoli can also impact plant growth and reduce yields. Severe infestations can sometimes mean no harvest at all. Doing your best to reduce the number of broccoli pests in your garden means not only fewer creepy-crawlies making their way into your harvests but also more veggies on your plate.
Most of the common broccoli pests covered in this article also attack other brassicas too, including kale, Brussel sprouts, cauliflower, collards, and other vegetables. Though most of them are not “true bugs” (insects in the order Hemiptera with 6 legs and 3 body segments), I use the term ‘bugs” to refer to them throughout the article since not all of these pests are insects (slugs and spider mites, for example, are mollusks and arachnids). By using the term “bugs”, I’m able to include these non-insects in the conversation.
What to do if you find bugs in broccoli growing in your garden
When you come across a bug feeding on a broccoli plant, the first step is to get a proper ID. Take a good look at the critter. What shape and color is it? How does it move? Is it feeding on the broccoli leaves, the stem, or the florets? Is there a single bug there or a group of them? Are there eggs present on the foliage, too? All of these visual cues can help you make a proper identification.
Let’s meet some of the most common bugs found in broccoli plants.
What are those worms in your broccoli?
There are numerous species of what are often called “broccoli worms”, which are really not worms at all. Instead, they are caterpillars. These “worms” are the larvae of several different species of butterflies and moths that feed on broccoli plants. They are the most common insects you’ll find feeding on your broccoli, and it’s important to keep them in check because they can cause significant damage very quickly.
Common types of broccoli worms
- Imported cabbage worms (Pieris rapae):
In Europe, where this pest is native, it’s called the small white. It is now common across all of North America. The white, 1 ½” wide butterflies (sometimes called cabbage moths) are spied flitting around the garden. Each white forewing has one or two dark spots. The caterpillars are green with a faint yellow-cream line down their backs and covered in a soft fuzz. They grow up to 1-inch-long as they feed on your plants. They feed on the florets and the leaves and are often found on leaf undersides.
- Cross-striped cabbage worms (Evergestis rimosalis):
This type of broccoli worm was once only found in the Southern US, but its range has greatly expanded in recent years. It is now found as far north as New England and as far west as the Rockies. Eggs are laid in small groups and the young caterpillars sometimes feed in groups, too. The adults are small, night-flying moths that you seldom see. The worms are light gray with black bands across their backs and a yellow line down their sides. The underside is a greenish yellow. Before they pupate, they reach about 3/4″ long. They are mostly found feeding on the leaves and can completely skeletonize foliage so nothing is left but the stem.
- Large cabbage white butterfly caterpillars (Pieris brassicae):
The large white is an extremely destructive bug in broccoli patches. It’s common across Europe and Asia. Reports of a few populations have also been noted in the northeastern US. The adult butterflies look similar to imported cabbage worms – white, day-flying butterflies with black dots on the wings – but the butterflies are larger. The caterpillars feed in large groups. They are greenish-yellow with black dots and bristly hairs. These broccoli pests can completely defoliate a plant very quickly.
- Diamondback moth caterpillars (Plutella xylostella):
These small broccoli worms are segmented and have tapered ends. If you touch them, they wiggle around and may even drop from the plant. The adults are small brown moths (less than a half inch) and hold their wings folded up in a tent shape. At nighttime, the adults migrate northward as the summer progresses, laying eggs along their journey. Diamondback moth caterpillars feed primarily on the leaves of broccoli, making small holes in the foliage.
- Cabbage loopers (Trichoplusia ni):
The cabbage looper is not as winter hardy as some other broccoli worms, but it migrates northward readily throughout the summer. That’s why the further north you live, the later in the season this pest is noticeable. The nocturnal adults are small and brown with a white mark on each forewing. The caterpillar is light green and can grow up to 2 inches long. One unique feature of this caterpillar is that it can arch its back into a loop shape (like an inchworm). Loopers feed on both the broccoli head and the leaves.
How to keep worms out of your broccoli
After you’ve identified that the bug on your broccoli is a broccoli worm, it’s time to get them in check. Here are some useful methods of control for these caterpillars.
- Row cover: Lightweight and useful all season long, row covers are placed over broccoli seedings and left in place until harvest. Since broccoli prefers cooler weather, use the lightest weight row cover possible to prevent heat from building up beneath. Pin down the edges of the row cover and prop it up using a mini hoop tunnel. It forms a barrier to the adult butterflies or moths, preventing them from laying eggs on your plants. Always grow broccoli under row covers. It really is the simplest way to keep worms out of your broccoli patch.
- Companion planting: Though there are many folklore-based companion plants touted for keeping various broccoli worms off your plants, only a handful have research to back them up. Interplanting with chamomile, dill, and cilantro has been shown to reduce egg laying. Companion planting broccoli with herbs with small flowers, like parsley, fennel, chervil, and dill has also been shown to attract the beneficial insects that feed on broccoli worms.
- Product controls: There are a handful of very useful organic insecticide products that manage various worms and other bugs in broccoli. My favorite is Bt (Bacillus thuringiensis), a bacteria-based pesticide that controls caterpillars of all sorts. Another useful product control for bugs in broccoli are those based on Spinosad, a fermented soil bacterium. There are several brands, including Captain Jack’s Deadbug Brew and Monterey Garden Insect Spray. Use products only according to label instructions.
Other common broccoli pests
In addition to broccoli worms, there are several other bugs you might find feeding on broccoli plants.
- Slugs: Finding these slimy bugs in broccoli is definitely no fun. They tend to prefer young broccoli seedlings but can also be found munching on the mature foliage. Nocturnal feeders who thrive in wet conditions, slugs leave behind ragged holes and slime trails. Use iron phosphate slug baits to keep them in check.
- Whiteflies: Whiteflies are tiny flying insects with white wings. When the plant is disturbed, they fly off in a cloud. Whitefly nymphs do not have wings and feed by sucking plant juices. They are often found side-by-side with the adults in clusters on the leaf undersides. Insecticidal soap or horticultural oil can bring them under control.
- Aphids: There are several species of aphids that feed on broccoli plants, including turnip aphids (Lipaphis erysimi) and cabbage aphids (Brevicoryne brassicae). These small, pear-shaped insects are found sucking sap from the plant in groups. If predatory insects like ladybugs and lacewings are not in your garden, the aphid population can grow quickly. They feed primarily on the underside of leaves, not on broccoli florets. Blast them off with a sharp stream of water from a hose, or use horticultural oil or insecticidal soap.
- Flea beetles: These tiny, black beetles hop like a flea and leave tiny, shot-like holes in the leaves. They are common bugs in broccoli patches where the most damage they cause is when they attack newly planted seedlings. They do not bite people, but they can be quite destructive in the vegetable garden, also attacking radish, eggplant, and tomato leaves. Neem oil and Spinosad-based products help manage flea beetles, in addition to row covers.
- Harlequin bugs: These shield-shaped colorful bugs might look festive, but they are very destructive to all brassicas. They are most prominent in the Southern US but their range is rapidly expanding northward. With a piercing-sucking mouthpart, they suck juices from plant leaves, leaving scarring behind. Spinosad-based products and row covers are the best management tools for harlequin bugs.
- Others: There are several other, less-common bugs in broccoli plants that might cause you issues in the garden, though to a lesser extent. These include thrips and spider-mites. And there are two pests that attack the stems and roots of broccoli plants, cabbage root maggots and cutworms, but you are not likely to find them on the leaves or florets. Cutworms are easily controlled by making a cutworm collar from a piece of paper towel tubing and putting it around the base of the seedling when planting.
Watch this video to see some of the pests in my broccoli plants and learn 3 easy ways to get rid of them:
How to get rid of bugs in broccoli after harvest
If you don’t discover the bugs in your broccoli until after harvesting the heads, there are a few ways you can keep these critters off your dinner plate.
After harvest, give the broccoli a salt water soak in your sink or a large stock pot. Mix a cup of salt with a gallon of cold water and soak the broccoli in it. After 10 to 15 minutes, the pests will float to the top and can be skimmed off. Rinse the broccoli with fresh, unsalted water before preparing.
You can also give your broccoli a soaking in a diluted vinegar solution of 1 part vinegar to 3 parts water. Any lurking pests will soon float to the top and can be removed. Rinse the broccoli before cooking.
And just in case you miss any broccoli worms via a salt or vinegar soak, when cooking broccoli (whether steaming or boiling), any worms present will always make their way to the top. It’s easy to spot them as they will be lighter in color than the broccoli. You can easily pick them off before serving.
Now that you know how to ID common bugs found in broccoli and keep them in check, I hope you’ll enjoy a hearty and prolific broccoli harvest from your garden each season. Our articles on growing broccoli from seed, when to harvest broccoli, and what to do when broccoli goes to flower may also be useful to you. If you’re looking for more ideas on how to organically manage pests in your vegetable garden, check out our online course Organic Pest Control for the Vegetable Garden.
For more on managing common garden pests, please visit the following articles:
- How to get rid of slugs
- What is that caterpillar on your tomato plant?
- Getting rid of squash bugs
- Four lined plant bugs
- Companion plants for peppers
Pin this article to your Vegetable Gardening board for future reference.