How to Stop Cabbage Caterpillars From Eating Your Garden!
Are cabbage caterpillars eating your garden? Out of all the pests I have covered so far, I think the cabbage caterpillar (also known as the cabbage worm) might be the one that we have all battled at some time or another. In my experience, the best way to stop green cabbage caterpillars from eating your garden is a multi-prong approach that deals with each stage of this butterfly’s life.
Yes, I said “butterfly.” As gardeners, we are usually ecstatic when we see butterflies fluttering about the garden, but there is one butterfly that always makes me cringe a little—the cabbage white butterfly. This butterfly lays its eggs on brassicas (kale, cabbage, broccoli, etc.) and those eggs hatch into those green caterpillars that devastate our brassica patches.
Identifying The Cabbage White Caterpillar
What are those green caterpillars eating my garden? It would be a good time to note a couple things: First, each garden zone will have different native pests, so while I can identify the types of green worms we get in zone 10b, there are other kinds that might be native to your zone. Therefore, it is definitely worth it to check and see what kinds of butterflies and moths are native to your area. Second, I have two kinds of green worms in my garden: cabbage white caterpillars (AKA cabbageworms) and cabbage loopers. This year it seems the loopers are more prevalent.
Cabbage white caterpillars are the larvae of those white butterflies I mentioned previously. You can often see them flying above your brassicas. When they land, you might see their abdomens curling under and depositing an egg on the underside of the leaves. It’s easiest for me to identify cabbage white caterpillars because they look like velvet or slightly fuzzy.
Cabbage loopers are the larvae of the looper moth. It’s a greyish looking moth that I don’t often see in the garden because it is mainly nocturnal. These green caterpillars are not velvety and actually move in more of an inchworm pattern. They have to move by bending their middles up and down because they have no middle legs! If you look at the photo below, you’ll see little legs in the front and back. As I said, this year my garden has tons of cabbage looper caterpillars.
How to Stop Cabbage Caterpillars From Eating Your Garden
Like I was saying in the beginning of this article, it is best to control these cabbageworms by using a multi-prong approach at all stages of this caterpillar’s life. In the rest of this article I discuss my recommendations for how to approach these pests in the garden.
Companion Planting to Deter Cabbage Butterflies
Your first line of defense is companion planting. Why? Planting your brassicas amongst plants like calendula, nasturtiums, garlic, or onions can help to confuse the butterflies and “hide” your brassicas so they can’t find them. For example, this year I had great success by interplanting my cabbages amongst dense calendula and garlic patches. As a result, I felt like the strong fragrance of the garlic made it hard for the butterflies to find their host plant.
Nasturtiums are another great companion plant. They are a great example of a “trap crop” that lures the pests in and basically sacrifices themselves for your vegetable garden. In this case, the cabbageworms would inhabit and eat the nasturtiums instead of your cabbages. For more flowers that are very useful in the garden, I highly recommend reading “Best Flowers for a Potager Garden.”
Physcial Barriers – Another Organic Option
Your second line of defense (should you choose to use it) would be to use a physical barrier to prevent the butterflies from laying their eggs on your brassicas. Personally, I find physcial barriers to be the most effective method for stopping cabbage caterpillars from eating your garden. There are a few interesting phyiscal barrier options:
Lightweight fabric covers. This fabric is specifically designed to let enough light in to your crops, but also will prevent the butterflies from being able to lay eggs on your brassicas. For an example you can check out my full DIY fabric row cover article for how to install your own. In addition, some gardeners have success using tulle or other screen fabric too.
Wire cloches: These would not be long term solutions because of their size but, most of the time, my goal is to protect my brassica seedlings long enough for them to get big enough to fend for themselves. Therefore, decorative cloches could be used until the plant is too big to fit. At this point, damage from pests is not usually fatal. Moreover, these cloches would also protect from birds, curious dogs, and maybe some curious rabbits.
Pest Control Pop-Up: I have never used these, but they look to be an awesome solution for small garden beds and spaces. For instance, if you are looking to easily cover one bed, these pop-up tents might be a solution. It seems they let enough light in so your plants can still grow, but they will keep out a variety of pests. However, a cover of tulle would probably do the same.
Find & Remove Caterpillar Eggs
After doing all you can to prevent the butterflies from laying eggs on your brassicas, the next best course of action would be finding and squishing any eggs. Do this daily! To find eggs, look on the undersides of brassica leaves for tiny, creamy specks. If you look closely, they should look like an oblong egg. Some gardeners will take an old toothbrush and softly brush the undersides of the leaves to remove the eggs or simply rub the undersides of leaves with their fingers. Either way you do it, target these eggs to prevent them from hatching into those green caterpillars!
Most importantly, daily inspections are vital to garden success! Even if you can get outside for only five minutes, do it! Take time to enjoy looking at all your plants. Check for signs of disease, bug bites, caterpillar poops, drooping, etc. Knowing your garden is the key to catching things early and preventing a full blown problem in your garden.
Related Article: What else usually grows with brassicas? Check out my Fall & Winter Gardening Guide for SoCal!
Despite all our efforts, finding these little green buggers on our brassicas is inevitable. The last resort in our multi-prong approach is looking for the caterpillars on the plants and squishing them, feeding them to chickens (or quail), or drowning them in a bucket of water. PS: I totally use gloves for squishing or throw them on the ground and step on them. Since cabbage caterpillars are green, they blend in very well and are hard to spot. Start by looking for holes in the leaves or caterpillar poops. These are the best indicators that a caterpillar is nearby.
The Role of Beneficial Insects
I wanted to end this article with a very cool story. For the longest time Sam and I had had what we deemed the prettiest kale we ever grew. It was a curly variety, grown from seed, and was absolutely lush and perfect—no bug holes! We had no idea why this kale was absolutely caterpillar free until we met Steve. Scary looking and hairy, Steve was our resident garden spider. One day we looked inside the kale and saw him with the drained body of a cabbage caterpillar hanging out of his mouth. It clicked! Our kale was flawless because Steve was eating all the caterpillars on it—major points for mother nature!!! Steve scared the heck out of me, but I knew he was responsible for keeping our vegetables pest free. Additionally, critters like birds and certain kinds of wasps can also prey on these caterpillars. At the end of the day, it’s so important to recognize the role of beneficial insects in keeping these cabbage caterpillars from eating your garden.
Related Article: Cool Season Flowers for Southern California
In conclusion, staying vigilant against these caterpillars is the key to controlling them organically. I would try committing to trying these methods for a whole season and see if you have less damage. Currently, we employ all of these methods in our garden and I can honestly say that we don’t consider these caterpillars to be a problem.
Still Having Really Bad Caterpillar Issues?
I have written an article called “My Organic Pest Control Toolkit” that outlines some of the more severe means by which you can deal with pests. I only use these methods as a last resort! Remember, the goal is to have balance in the garden—-not insect free! Click here to read. Coming Soon!
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