As soon as the brassicas and kale start growing in the early spring or fall garden, the dreaded cabbage moth and her cabbage worms make their appearance. Knowing how to get rid of cabbage worms naturally can feel daunting, but over the years, I’ve discovered some helpful natural tips that fit almost everyone’s gardening style. And if you happen to have backyard chickens, they may benefit from your gung-ho, get-rid-of-worms attitude.
What are cabbage worms?
If you begin to notice holes in the leaves of your kale, cabbage, bok choy, cauliflower, or really any member of the brassicas family, then chances are you’re dealing with cabbage worms.
Cabbage worms are a pale green, almost the same color as the leaf and stem of many of your spring and fall favorite plants. Even if you can’t see the worms, they may still be present.
When looking for cabbage worms, check the under sides of the leaves, they are very rarely on the top side of the leaf. And be sure to also check down where the leaf meets the stem, since this is the perfect hiding spot for tiny worms.
Cabbage butterflies, white butterflies with a black dot on each wing, are the culprit in bringing cabbage worms to the garden area. Seeing these butterflies is a good indication that you need to be on the lookout.
How to Prevent Cabbage Worms
Prevention really is the best defense in all areas of pest control in the garden. Preventing cabbage worms means keeping a lookout for the cabbage butterflies, with their white wings with a black dot on each.
The newest technique for preventing cabbage worms that I’ve discovered is using butterfly decoys. I ran across a post on The Good Seed Company blog, all about how cabbage moths are territorial. This means, they don’t like to lay eggs where other cabbage moths are already present and “working.” The decoy, which can be printed from their page here, are hung on string and dangle near your brassicas and greens. Ideally, the moths will see these paper moths and choose to go elsewhere.
It’s an interesting concept that I was excited the first year to actually see them work. For me, it was a great way of using a non-chemical method of keeping the butterflies away from my brassicas.
Light row covers that are permeable by light and water are also a good choice for prevention. If the cabbage moths/ butterflies can’t get to your plants, then they cannot lay eggs. Problem solved.
Damage Caused by Cabbage Worms
What if your cabbage worm prevention comes a little too late? I take a live and let live attitude with some bugs in the garden, as long as they remember who’s in charge. In my book Natural Pest Control for the Home Garden, I identify common pests and beneficial insects, so the home gardener can tell the difference. We certainly don’t want to kill any bugs that are working FOR us, right?
However, cabbage moths and the worms that hatch from the eggs they lay can decimate greens and brassicas. And when I say decimate, I mean they can take a perfectly healthy leaf and devour it. My kids are cheering for the cabbage worms to eat up all of our kale, but not on my watch. Here’s one of our broccoli leaves that had recently become a snack for cabbage worms. If left unchecked, they would easily consume this entire leaf and others that were on the same plant.
Over the years, I’ve tried many methods for getting rid of cabbage worms. Here are the ones that I’ve found to be most helpful, and one that we’ve just started trying, so I’ll have to let you know how it goes. I do try to keep my gardening as organic as possible, so no Sevin dust or other chemical bug killers will be found in my list. To each his own in the garden, but with kiddos picking and eating freely from the garden, I want to get rid of cabbage worms as cleanly and pesticide-free as possible.
How to Get Rid of Cabbage Worms Naturally
- Seek and Destroy– As the name implies, this simply means going out, checking under leaves and in the base of plants, and picking off worms and eggs. It’s about as fun as it sounds, but interestingly enough, some kids LOVE it. I have a jar of soapy water handy and the worms get placed in the jar. If you happen to have chickens, put the picked-off worms in a little container, and then feed them to your little chickies. Obviously, there’s nothing you have to purchase for this method, but you do have to be vigilant about checking your plants.
- Flour– A pantry staple and also an effective worm killer. Dust flour on leaves where worms are present, and they will eat the flour. The flour dries them out, especially in combination with the warm sun, and boom, they’re dead. I have repeatedly used this method in the past, and while it is effective, it did tend to discolor the leaves of my plant. This isn’t a huge issue for cauliflower, broccoli, and brussels sprouts, but for kale and other plants where the leaf is eaten, I prefer to use something else. For application, take an old plastic jar, punch holes in the lid, fill it with flour, and then shake onto leaves. Very simple!
- BT (Bacillus Thuringiensis)- Though I tend to think that names I cannot pronounce are automatically harmful chemicals, BT is actually a bacteria that is harmful to cabbage worms and other invasive worms. It does not harm humans or other beneficial insects. I first learned about BT from several garden Youtubers (is that a word?) whose channels I enjoy and trust. MIGardener and Epic gardening both practice organic gardening techniques and use BT sprayed on the leaves of plants to battle cabbage worms. The worms eat the BT off of the leaves and once in their system, the BT develops toxins inside the worm. This toxin causes the worms to stop eating and then eventually die. For application, use a garden spray bottle and follow the mixing ratio on the bottle. Plants will need to be sprayed every few weeks to keep the BT on the leaves.
- Cabbage Moth Decoys– As mentioned above, these cabbage butterfly/ moth decoys can also work if you see if you already have a problem with this pest. Simply use one of the natural methods above to get rid of the cabbage worms, and use these decoys to prevent any more eggs from being laid.
So now you have four different tactics to combat the dreaded cabbage moth and cabbage worms. I’d love to know if you have any other techniques for getting rid of or preventing these plant-loving eaters. If you’re looking for a more comprehensive guide on garden pests and how to control them without harsh pesticides (that kill pollinators and beneficial insects, too) check out my book Natural Pest Control for the Home Garden!
Other Natural Pest Control Methods
Have a great week and happy gardening!