Cabbage Moth White Butterfly: 10 Tips for Brassica’s Kiss of Death
Are you struggling to grow brassicas without those awful green cabbage worms? The cabbage moth (white butterfly) is to blame and I’ve only recently come to know its name and its infamy.
When I was young, I loved running through the field on our property chasing after the white butterflies. I’d catch them and then let them go, only to catch them again. So much joy!
As a mom, I smiled fondly at my daughters doing the same, calling out, “Flutter!” – the name they’d chosen for the white butterfly that loved our garden.
It spent so much time in our garden, especially near our brassicas – our kale, broccoli, cauliflower, and brussels sprouts. Soon I became suspicious as I discovered that this was actually a cabbage moth – the very white butterfly creating these awful green worms that ate everything to tatters.
I quickly learned just how destructive cabbage white is to the garden, especially to brassicas.
And so, I’ve set out to deter and eliminate the cabbage moth from our garden in just about any way possible!
If you just want to grow your brassicas in peace, follow along and hopefully we can get through this together!
What is the cabbage moth (Cabbage White)?
Commonly called the cabbage moth, the cabbage white butterfly is scientifically known as Pieris rapae. It’s a member of the white and yellow butterfly family, Pieridae. Small to medium in size, this butterfly is more of a garden pest, creating larvae that can easily devour entire leaves of brassica plants in a matter of hours.
Surprisingly, (or unsurprisingly, I suppose, for more experienced gardeners) this butterfly is considered one of the most invasive agricultural pests the world over.
What does the cabbage worm look like?
The cabbage white caterpillar (or cabbage worm) is almost identical in coloring to the shade of green found in many brassicas. It blends in almost perfectly to kale, broccoli, and so forth. So, please dear gardeners, be sure to look closely before you take a bite!
What do cabbage white caterpillars eat?
The cabbage white butterfly lays its eggs on brassica vegetables. The cabbage white caterpillars soon hatch in the perfect place to absolutely decimate your brassica plants – kale, broccoli, cabbage, cauliflower, and brussels sprouts, to name a few. As an adult, the cabbage white butterfly consumes nectar.
If you see lots of holes in your brassica greens, or leaves eaten down to the spines, you may have a cabbage worm infestation on your hands.
How to Get Rid of Cabbage Moth
Preventing brassica damage starts with deterring or destroying the cabbage white butterfly.
Killing the cabbage white is a bit rough for me, as I always thought it was a sweet butterfly until VERY recently.
However, I believe for the sake of our garden plants, and our hard work and enjoyment and all that – I’ll put on my game face and go full flipflop ninja on this beast.
You guys with me?!
Get Rid of Cabbage Moth
Here are some tips and steps on how to get rid of the cabbage white butterfly.
1. Smash the white butterfly out of the air.
I feel badly about this. I do. But I’m sorry, cabbage white butterflies don’t pay the grocery bill, so there it is. The ‘sole solution’ is a swift whack with one of my Havaianas. (The most comfortable flipflops ever, in case you have yet to enjoy them! Highly recommended!)
2. Hand-pick to remove green cabbage worms from the plants.
Also sad, but necessary. Look on top of and underneath leaves. Drop them in a bucket of soapy water to reduce the population and start claiming your brassicas back!
3. Cover brassicas with insect netting, wire baskets, or cloches.
You can DIY the perfect cabbage moth shield with some tulle or true insect netting / row covers. If your brassicas are small enough, you can also use wire wastebaskets from the Dollar Tree as a protective cloche.
4. Try self-rising flour.
Anecdotal advice from many gardeners suggests you can use a dusting of self-rising flour to get rid of cabbage moth larvae.
5. Apply a topical pesticide or treatment.
If you aren’t strictly organic, consider pesticides as a last resort. Some gardeners recommend Thuracide BT or Neem oil to kill caterpillars of the cabbage white. (Although, please read for special considerations of bees and pollinators.)
6. Search for the yellow eggs and remove them.
Cabbage butterfly lays her eggs underneath the leaves. The tiny yellow eggs likely blend in if you don’t know what you’re looking for.
7. Mix up a dish soap and water spray.
I use a spray bottle from the dollar store and put a small squirt of Dawn dish soap to a full bottle of water. Mix it around and spray directly on the plant in the evening. You can rinse it off after 45 minutes to an hour. Try not to let the sun get to it.
8. Try cabbage white butterfly decoys.
Some evidence suggests these creatures are rather territorial and won’t come super close to another on a plant. Affix a white bread tag or get custom cabbage white butterfly decoys to try your luck.
9. Consider companion plants like marigolds, dill and lavender.
Some companion plants lend beneficial properties to help ward off pests. Thyme, garlic, and oregano might also be worth a shot.
10. Try your luck with cabbage butterfly trap crops.
You may find that plants like nasturtiums make excellent trap crops for cabbage white. Plant them at the end of a row or even consider planting other unwanted brassicas as a trap crop in another part of your yard. (Plant these several weeks earlier, if possible, to allow them to be larger and more attractive to the cabbage whites.)
Final Thoughts
If you do nothing, the cabbage moth will eat you out of house and home. Well, at least as far as your brassicas are concerned. It will literally destroy your entire crop.
Between this supreme garden pest and the vine borers and squash bugs, our garden harvest was more disappointing last year than we expected.
This year we are determined to do a better job targeted specific pests we’ve endured already. The cabbage white decimated our entire brassica crop so this means WAR!
Are you also at your wits end from the cabbage white butterfly? We sure are! Let’s conspire in the comments below!
06.16.22 – Edited to improve spacing between elements. Focused more on cabbage moth. Added new photos.
Bird netting heaped on finer insect netting is confusing to them and they often get trapped between the layers as they try and find a way in. Attach small bells to bird netting to alert you to any trapped birds and check netting often.
Carry a pocket full of long elastic bands – It’s more of a sport if you have a reasonable chance of missing your target, plus they are useful for a quick tying-in of plants if you place a stick between the loops. Practice your aim, and be sure to recover your bands after use.
Hi Mr. P! Loved your comment – thanks for these fantastic tips. The cabbage white got inside the little netted food tents I put over my broccolini this year, so I definitely think your tips will be in order. I have some fine white tulle netting and some bird netting I can use. I really like the detailed explanation of how to set that up with the bells. Thank you for sharing. The bands sound fun too – my 9yo daughter will be totally into that! Sounds better than chasing them around the yard with a flipflop.
– Kate
Yes I have tens of them daily, and so I swat them with a batminton racket…but it keels me running after them…lol
Hi John! Glad it isn’t just us! Flipflop is my choice of defense. My daughter chases them too, and I also spray them away with the hose. I laugh this year because I didn’t get around to planting any brassicas yet and I see them fluttering through my garden with nothing to terrorize!