How to Deal With Cabbage Worms

cabbage worm damage

It happens every year. I forget the gardening lessons of the year before. Take my many failed attempts to grow cabbage, for instance. It always gets decimated by the imported cabbage worm (Pieris rapae), a creature as abundant in Los Angeles as aspiring actors.

There are several strategies I could use to deal with this pest (cabbage worms, that is–I have no problem with actors). I could spray Bacillus thuringiensis but I don’t like the idea of killing non-target species, not to mention the disputed human health effects of BT. I could use row cover, but this winter has been way too warm for even the thinnest material.

The best suggestion comes from the University of Florida. Find resistant alternatives:

Crucifer crops differ is their susceptibility to attack by imported cabbageworm. Chinese cabbage, turnip, mustard, rutabaga, and kale are less preferred than cabbage, collards, Brussels sprouts, broccoli, and cauliflower. Some cultivars of certain crops also have moderate levels of resistance to infestation by imported cabbageworm. One resistance character is due to, or correlated with, dark green, glossy leaves. This character imparts resistance to imported cabbageworm and other caterpillars, but increases susceptibility to flea beetle injury (Dickson and Eckenrode 1980).

cabbage2

I’ve noticed that the huge Franchi “kale” (collard?) that has gone into its second year, seems to be less popular with the cabbage worm than the adjoining Portuguese cabbage. Next year, I’ll skip the cabbage and plant something else. I like mustard better anyways. If I want cabbage I can outsource the growing and pick it up at the farmers market.

Have you had problems with cabbage worms? How have you dealt with it?

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27 Comments

  1. “Have you had problems with cabbage worms?”
    I don’t think anyone would answer no to that. afaik this invasive species is everywhere, even where, like me, there are many hard freezes. Spraying is the most tedious thing to do — hate it! Here is what I do:
    1. Do Permaculture. If you can think of gardening only in terms of agriculture and its monocrops you are only setting it up for pests. You want to grow a community of mutually beneficial plants, just like nature. You don’t look at my garden and say that is where I am growing cabbage but you will see cabbage, dill, cilantro, chives, onions, garlic and marigolds.
    2. Go big. Even if do the above and make your plants strong by composting, etc you will not eradicate the cabbage worm. So grow enough where it doesn’t really matter. The nice, neat, controlled little garden spaces most have, is not enough. Grow everywhere. Tear up the streets and plant there.
    3. Get a butterfly net. This probably won’t do much but make you feel better. And Chickens love them.

    • “Do Permaculture?” It doesn’t sound like you’ve grown much before althouh yes if everyone practiced permaculture methods the world would be a much beter place!… One of the preferred methods which can be part of a permaculture system (you can use it while growing organic, “pesticide-free” vegetables) is potassium salts aka Insectidal soap… you spray it on the plants to keep the bugs from devouring them– I suest buyin the concentrate and mixing it yourself to save money! http://www.treehelp.com/safers-insecticidal-soap/

    • I think they might be worried about ingesting Bt –because GMO crops are designed to produce Bt, which causes bugs that eat its stomachs to explode… a lot of people worry (and there is some evidence to support this, like bT in the bloodstream of pregnant women who eat GMO corn) that some of the Bt doesn’t break down before it enters the human food system, and might be harmful.. handling Bt is fine….

  2. What about planting a sacrificial cabbage that is very attractive to cabbage worms to bait the egg laying adults and growing a less susceptible brassica for people food?
    My only brassica (kale) is under a couple of feet of snow right now and I am pretty sure it is not being bothered by cabbage worms!

    • Yeah that’s what I might try. Maybe I will pick up a 6 pack of cabbages and plant them nextish to my kale that will be covered with floating row cover. I find the row cover works pretty well. I also got these netted tunnel things on super clearance a few years ago and they work even better because it takes quite awhile for the net to contact the plant. I have had them get into the crops under the row cover and the only thing I can think is that they laid their stupid eggs on the netting and it got through? I dunno. Hate them.

  3. For three or four years I tried growing a few brassicas, and had to diligently squish cabbage loopers. This fall, I planted a hugh amount (for me; it is all relative): cauliflower, broccoli, kale, red and savoy cabbage, and brussels sprouts. I sprayed BT when the damage reached a “bad” threshold. It knocked back the worms, but they came back. I planned on spraying again, but life interfered, and I put it off. Then I noticed tons of wasps milling around the garden. I looked more closely, and the wasps turned out to be mud dabbers. The mud dabbers have, for decades, lived in my garage. I never remove their homes because they don’t sting, and I like the idea of insect building with a form of adobe 🙂 Anyhoo, to make a short story longer, the mud dabbers decimated the cabbage looper population. I don’t know why they never fooled with them before. Maybe I didn’t plant enough brassicas for the cabbage looper population to reach some critical threshold to cause the mud dabber to say “Wow, this here groups of worms is definitely worth my hunting and gathering time!” The sad ending to the story is that grey squirrels, who before this year hadn’t paid attention to any brassicas, must have gotten the news about that group of vegetable’s health benefits, and have totally decimated my garden. I get really irked when I watch them perch in a tree with stolen produce, num up the tender part of the leaf, then toss the tough midrib to the ground. I must confess that when one squirrel was hit by a car as he/she tried to drag an enormous cabbage leaf across the street, I was not sorry. Gardening may well keep me out of heaven 🙂

  4. Yes, I have problems with them in NW Iowa. But here row cover is an option year round.
    In my smaller kitchen garden I can just hand-scrape the eggs and caterpillars off.
    My neighbor swears by diatomaceous earth for everything, but I think it mostly just deters the earwigs.

  5. Have you ever tried spraying with water, garlic, onion, cayenne pepper, cooking oil, Dawn mixture? It kept worms off my tomatoes and the few other things that did not include cabbage. I swear by this formula. Of course, I put it in a squirt bottle and laboriously spray my few plants, but it is easier than poison or picking/squashing. There is no poison residue and you can mix this in the kitchen blender with no fear of the results.

  6. I love collards and mustard – Giant Red Mustard being one of my favorite plants EVER! It is rarely bothered by the evil green devil worm in my garden, but the collards and kale do get hit. Twice weekly, I hit the undersides of every plant with a strong jet of water and it seems to do enough of a trick to keep the leaves from being totally decimated. I used to do chili/garlic spray, but I got suspicious that maybe it was the physical act of continually wetting the undersides of the leaves that kept the worms at bay, rather than the deterrence of the chili/garlic/oil/soap. Funnily enough, I might be right! I don;t see a significant difference between the chili mix and plain water! As for BT, I’m strongly against it. It gives me a sore throat within minutes of spraying it – I decided long ago if I can’t eat it, I don’t want it on my plants. I say the simpler the better! One of the reasons I LOVE THIS BLOG!!!!

    • You may be right about the continual blasting underneath the leaves. However, my “poisoning” was a puny hand spray bottle used on top of the leaves. I cannot bend enough to get underneath the leaves. So, I cannot say which of us is right except to say I will do my spray method from now on. My tomatoes are already seasoned this way.

  7. I stretched mosquito netting over my cabbage crop last year. It kept out 95% of the cabbage moths (how did the other 5% still get through a damn mosquito net?? Life finds a way). I’ve also been known to bash cabbage moths with a badminton racket when I’m feeling spry and destructive. But the mosquito net has definitely been the most effective. We made lots of sauerkraut.

  8. I had many, many problems in my small garden with cabbage worms. Two years ago I planted leeks and thyme near them, not on purpose, but it seemed to keep them away…I had very, very little cabbage worm problems with this Leek/Thyme/cabbage combination…The next year I did the same thing and it kept them away, as well…Oh, yeah, I threw in a few radishes near them, too…

  9. I, too, did not have success with row covers, which likely had more to do with my ineptitude with the clips and fabric and hoops, than the concept itself. I grow dinosaur kale, which grows through all weather and the worms ignore for most of the season, until everything else is gone and they’ve got nothing else to eat.

  10. I have grown brussels sprouts and kale in the past and not been bothered. This past summer the cabbage worms absolutely wiped out both these species. i decided to start kale to set out in fall. I eventually moved all 60 (I don’t know why so many) plants to the porch in preparation to move to the garden. The moths even found them there. I scraped and picked them off. It was a struggle. I finaly planted them in the garden and used a row cover. I won’t try to grow these plants again.

  11. My family (G-Grandparents in Kentucky) has always pulled a bottom leaf off the cabbage and put their ash from their wood burning stove on the leaf top of the cabbage the night before and come out early in the morning and burn the leaves, The worms were drawn into the wood ash.My mother and myself have used panty hose secured over the plant and both ends tied off. Plant could grow and get bigger but bugs couldn’t get on them. If I haven’t enough panty hose, I hit up garage sales and pick up shear curtains and make a large bag and slide over the cabbage so it can still grow and secure it at the bottom and the moths can’t lay their eggs to grow those icky worms…..

  12. I use coffee grounds. I save them up during the winter (I live in the North East) and in early spring spread them over the garden about a month before planting. It does an excellent job keeping away colorado potato beetles, cabbage worms and aphids for the entire season.

  13. TKL has the right idea- there are many hornet or wasp type insects that feed on aphids and all kinds of things that bother brassicas. I used to scrape the beginnings of hornets nests off the eaves at the back of the house (I have two sliding glass doors and I can’t for the life of me figure out ,i>why they have to build right over my egress) but don’t anymore. I noticed them hovering around the cabbages and wondered what they were looking for and later read that they are a beneficial insect. So now they are my friends.

  14. Cabbage worms are the bane of my existence. I read somewhere that the butterflies don’t like competition, so if you hang decoy butterflies around the yard they won’t bother your crops. I tried that: cutting butterfly shapes out of yogurt containers and painstakingly hanging them on fishing line around my plants, and almost immediately, I swear I could see every damn white butterfly in the neighborhood come flying into my yard. Obviously, the yogurt cup butterflies got promptly ripped down.

    I find that the curly kale does much better than the dino kale, and significantly better than the cabbages.

    I cover my beds with tulle from the fabric store. On sale, its only like .50 a yard, much cheaper than row cover. And as long as a fly doesn’t get under and then the cats make it their life mission to get said fly, it tends to last pretty long.

  15. They are destroying the yellow chard and Lacinato kale in my Fullerton garden. They don’t seem too interested in the Red Winter Kale. I hand pick and give them to our chickens, and also spray off the leaves. This has worked well with my broccoli in the past, as long as I am consistent with it. The greedy buggers only appeared in my garden in the last couple weeks and I was slow starting the fight against them. Thank you for the post about them, it inspired me to go out tonight and see what was eating more than I want to share. I have the ones I picked off tonight in a jar, they will be a nice breakfast for the girls tomorrow.

  16. What about a couple guinea hens?They are bug eaters only.And do not scratch the dirt.So they would not work for cutworms but they would get cabbage loopers,and squash bugs.I haven;t worked with these birds but have been trying to learn about them.They lay eggs too.
    For a tasty ,really glossy collard green I got a variety called Cascade Glaze from Territorial Seed.It barely even gets aphids it is so glossy/slippery.(I see Territorial does not have it this year.)Will have to search somewhere else.

  17. how about kholrabi? taste a lot like cabbage you can eat it raw as a slaw or steamed baked and in curries. Ive just discovered it and its yummy 🙂

  18. I used to do what Karen B does (6 year old) but the kids grew up 🙂

    Here in the Westchester neighborhood of L.A. we have had great success by planting cilantro all around the brassicas. Somehow it seems to distract the cabbage whites and you get a whole lot less of them, which has the effect of leaving enough cabbage/kale/collard for humans to eat!

    You plant the cilantro seed at the same time as, or slightly before, the broccoli family plants. It won’t do much good if you’ve already suffered an attack. Put it in the garden journal for next year.

    I notice that the spontaneous compost volunteers of cilantro seem to come up in autumn, before the broccoli gets planted. So I transplant those volunteers into the space where I’m seeding the broccoli family, plus seed additional cilantro.

    We harvest bundles of cilantro, plus let some go to seed. The lacy flowers are great for attracting hoverflies (a very effective pollinator).

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