How to Get Rid of Broccoli Worms in Organic Broccoli, Cauliflower, & Cabbage
If you grow broccoli organically you’ve encountered broccoli worms at some time in your gardening career. If you buy organic broccoli at the farmer’s market you might even find them hiding among the flowers. But broccoli worms don’t need to turn you off broccoli forever. There are a few things you can do in the garden to prevent cabbage butterflies from infesting your food with their offspring. But if all else fails, here’s how to make sure you don’t serve broccoli worms with dinner.
My kids are pretty squeamish about eating bugs. That has sometimes meant that they are totally traumatized when I serve homegrown veggies. One son has post-traumatic stress when it comes to eating broccoli — flashbacks to the day that I served him homegrown broccoli, microwaved, and he watched, in horror, as a single, sickly green broccoli worm slowly inched its way out of the “tree” on his plate. I stopped using a microwave for cooking a few years ago.
This is the cabbage white butterfly, the most likely garden visitor to lay eggs on your broccoli, cauliflower, kale, and cabbage.
BT spray?
When you grow broccoli organically you get white and sulphur cabbage butterflies laying their eggs on the plants. These eat the leaves and turn into little green or yellow worms. The colour of the offspring varies depending on where you live.
You could spray with BT to kill the bugs, but that leaves a residue on the plant. You have a lot of BT already in your stomach if you have ever eaten GM food, so avoid adding more if you can. We are learning that BT isn’t as benign as was once believed. If I see a green or yellow caterpillar on a plant I hand pick it, squish it between my fingers and drop it on the soil. But with broccoli and cauliflower, the little green worms are hidden in the florets. I just harvest the broccoli and deal with the little green caterpillars after harvest.
After harvest, you can soak out the broccoli worms
To draw the “broccoli worms” out of the broccoli trees, you need to soak it in a sink of cold water to which you’ve added 1/4 cup of salt and 2 tbsp of vinegar. You will need to keep the broccoli heads submerged in the water for at least 20 minutes. Weighing them down with a plate to keep them underwater can help.
Mom-Fail with broccoli worms
Failure to take this step will result in little green worms crawling out of your broccoli and onto your plate during a meal — if you eat your broccoli cold. Or if you microwave your broccoli, the worms get a sickly green colour and crawl out of your broccoli. If you boil your broccoli till it’s bright, deep green before serving — it kills the worms and you can handpick them out of your “trees” before eating. Vegans won’t want to eat organic broccoli. Omnivores might just eat the broccoli worms and all.
Failure to take this precaution can spoil broccoli for your kids and make chemically sprayed, store-bought broccoli more desirable than homegrown. To this day, my eldest cannot eat broccoli. If only I had known then, what I know now — submerge broccoli at least 20 min and up to 1 hour in a sink of cold water to which you have added 1/4 c. of salt and 2 tbsp. of vinegar. The worms are immobilized and slide out of the broccoli.
This works for cauliflower and cabbage, too.
If you’d rather use an organic insecticide to combat the cabbage worms before harvest, there are several herbal options. Most combine natural soap (not detergent), strong-smelling herbs like hot peppers, and wormwood plus garlic.
Recipe: Herbal insecticide for broccoli worms, caterpillars (makes 1 litre)
Soak four garlic cloves for several days in one litre of cold water and then blend. This will kill ants, aphids, caterpillars and cabbage worms. A stronger brew can be made by using hot water and adding several hot peppers, ground up. If wormwood grows where you live, add a few sprigs of wormwood, too, and blend well. Once blended, add two tablespoons of grated pure soap to help the spray stick. Use spray when the solution has cooled. Spray the leaves of plants when they are young and when you see cabbage butterfly activity. Make sure you apply to the underside of leaves, as well. Reapply after rains or after watering, when you notice butterfly activity.
Wash off the solution before eating the broccoli.
An even better tip for broccoli worms!
Predatory wasps lay their eggs on the backs of cabbage butterfly larvae. When the wasp eggs hatch the predatory wasp larvae burrow into the flesh of the caterpillars and consume them. (Nature is violent!). You can encourage predatory wasps in your garden by planting dill and fennel around and in your cabbage and broccoli. Using this trick may even give you broccoli that is entirely free of cabbage moth caterpillars. And you get dill to eat, too. (You might want to Pin this tip.)
A recap
The Cabbage Butterfly, also called the White Cabbage Moth lays its eggs on broccoli, cauliflower, cabbage, kale, and other plants in the Kole family. The green or yellow worms consume the leaves of the plants and hide in the tight florets and wrapped leaves of the vegetables.
Planting dill will encourage predatory moths and cut short the life span of the worms. Spraying with the organic spray will kill them on your plants. If all else fails, soaking the produce in salt and vinegar before cooking will dislodge them from the vegetables, allowing you to serve broccoli, cauliflower, and cabbage without broccoli worms.
Don’t give up organic gardening because of the pests. You’ve got this.
Learn more about pest-free organic gardening from Joybilee Farm
DIY Insecticidal Soap Spray for Trees and Shrubs
I use BT or baccilus thuringesis on my cole plants. It is an organism that disrupts the digestive system of the worms of miserable white moths that are responsible for the devastation. Caution !! Bt kills all members of the butterfly family. If you have monarchs, swallowtails or any other type of decorative, beneficial butterfly around do not use!!
I’ve read and read up on the “worms” I have now found in my fresh broccoli from 2 different grocery stores within the past year. Thinking you might have an input? They are little half inch white worms with like small puffy rings as their body. My research has led me to believe they are maggots?? The last one I found was black so I’m thinking it was a dead one? Broccoli is my favorite vegetable and I cannot stomach it anymore after this second find. Thoughts??
This is a very useful post, thanks! I’ve soaked, covered, hand picked and practically run around my garden chasing butterflies.. I buy commercial, heavily sprayed within an inch of it’s life now.. it’s the only thing I buy like that but it’s the only broccoli I can eat.. I love Broccoli! Thanks again..
I have been hand-picking the worms and catching and killing the butterflies three times a day, covered the plants with sheer fabric, sprayed with insecticidal soap, and have a robin’s nest next to the garden, and I soak in salt water. No luck. My broccoli is just heading up, and it’s covered with so many worms that I cannot get them out. The heads are full of a kind of caterpillar that makes a sort of silk, so that even if they’re dead, they won’t come out of there.
The best I can find, after 35 years of gardening, is to start coles in the late winter inside and be done with them by the time the butterflies appear in June, or start plants for a late harvest in October. Because our weather is so unpredictable, it’s been quite difficult to beat the bugs to the growing season.
It sounds like you are dealing with forest tent caterpillars. They aren’t the green worms that are from the cabbage butterfly. You could cover the plants in the field to keep the caterpillars and the moths with their eggs off your crops.
I have found that a spray bottle of water, dish soap and a few drops of cinnamon oil works very well. Worms immediately react to this and leave plants alone.
I’ve had the best luck by growing my broccoli and kale under light weight garden fabric. Place the fabric over the plants as soon as they’re in the ground and bury the edges so the bugs can’t get in.
my young son and i are growing vegetables, trying to become self sustaining. and we just discovered our broccoli has the green worms with the eggs on the underside. my son wants us to go take our dill weed and dill seed for our spices and put it around broccoli…cannot hurt???? we have a beautiful kale plant close by…do you think it is in danger of becoming infested as broccoli is. we are also thinking of uprooting broccoli so i will not spread. any thoughts? thanks for sharing your wisdom with all of us neophytes.
The worms that are already on your broccoli won’t be disuaded by the dill, unfortunately. The dill works in two ways. It disguises the sulfur smell of the brassica to “hide” the plant from the egg laying butterfly. It also attracts predatory wasps that lay their egg on the caterpillers. Their larva consume the caterpillars from the inside. I’d suggest that you get some insecticidal soap spray and put it in a spray bottle and douse the top and underside of the leaves of your infested broccoli. Handpick any green worms you find on the plants. (I go outside with a bucket of soapy water and just drop the green worms into the bucket of suds.). If your growing season is just starting, your best bet is to find a couple of dill plants at your local nursery and plant them in the garden bed now to discourage further egg laying. If you plant dill seeds it will be a month or more before the baby plants are effective. If you plant nursery plants they will start working shortly for you. I hope this helps.
we just went outside and uprooted “her” and put her in a pot away from the other plants. she has immeasurable eggs on her, so much that the stems are grey [hundreds of eggs on top of another] i was afraid the kale that is nearby might get infested…so do you think we can save her???
also inquiring minds want to know… what do the eggs become???…do the eggs turn into butterflies, or does the worm become a chrysalis and then a butterfly ??
thank you for sharing your knowledge with us. we are very appreciative
Actually, it sounds like those are actually aphids that are on your stem.. take a paper towel and a gloved hand and run your hand up and down the stem to squish the aphids… then a blast of insecticidal soap.. you are too late to “prevent” aphids so now you have to kill ’em. Look on the underside of your leaves.. there are wee orange bumps and sometimes wee white bumps.. those are the egg masses.. just wipe them off.. check the underside of the leaves every day.. yup, every day.. those worms are very good at hiding, you won’t find them all at one go.. keep doing this and your produce will be better…. take heart in knowing that the butterflies don’t fly in the winter and you can take a break.. Best of luck.
We will be netting our whole brassica patch next time we plant. Our last lot was eaten in its entirety. Even the kids out there every morning squashing and every evening squashing bugs couldn’t keep on top of the things! Thing is, I’ve seen those green caterpillars on conventional produce we’ve eaten in the past. I am not sure exactly what their purpose is other than to make our brassica consumption difficult!
Linda, I found a new trick for keeping them away. Last summer I accidently planted dill with my cabbages, kale, and broccoli. I think I found 1 single worm all summer. That’s it. Just interplant a few dill plants right in your broccoli rows. The dill attracts a parasitic wasp that lays it’s eggs in the caterpillers and the wasp larva eat the worms and kill them before they can do damage and before they can reproduce. It was amazing the difference.
I found this information on an internet search. Thanks so much! I found that the worms stick in the broccoli after soaking, but if you swish each piece vigorously in the other sink that’s about 1/2 full of water, it dislodges them and they stay in the second sink of water. Then you can examine it and there are no worms in it at all anymore. I went over it with a magnifying glass and they were really gone!
I actually scarred myself with broccoli. I didn’t realize there were worms in it and I just gave it a quick spritz under the sink and began chopping. Yikes! I couldn’t eat broccoli for the rest of the season without my stomach flipping. I’m ready to try it again and will remember this tip. No more wormies in my food 😉
Created the greatest arctiels, you have.