Cabbage worms or the caterpillars of cabbage white butterfly look velvety, green and can quickly eat through your broccoli and cauliflower. These worms can quickly take over, eating holes in the leaves of brassicas. They can destroy leaves and slow the growth of broccoli and cauliflower plants.
Green worms or cabbage worms can be removed by hand from your broccoli and cauliflower, sprayed off with a hose or treated with a naturally occurring bacteria, Bacillus thuringiensis (Bt) which attacks the worms.
Green worms should be removed as soon as you see them because they can quickly eat through whole leaves. This will decrease the leaf area that the plant has to photosynthesize, which can slow the plant’s growth or even kill young plants.
This article will explore how to remove green worms from broccoli and cauliflower safely and naturally and ways to prevent them from attacking in the first place.
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4 Ways to remove green worms from broccoli and cauliflower
Here are the top ways to remove green worms from broccoli and cauliflower. These ways are natural and will not harm people or animals in your yard.
1. Hand removal
Wearing garden gloves you can gradually pick off the green worms from the plant one at a time. They can be quite sticky and will stick themselves to the leaves with a white substance that is tricky to remove.
Inspect the leaves closely because they blend in perfectly with the leaf color. I found more than 12 caterpillars on my broccoli plant who had slowly been eating away at the leaves for 2 days. In this time they had removed almost 50% of the leaf coverage.
It is best to go back to the plant and check again the next day. You can see if there are any worms that you missed that are still eating the leaves.
2. Pick them off with a stick
My preferred method to remove green worms from broccoli or cauliflower is to pick them off with a stick. Grab the stick and flick each caterpillar off. This keeps my hands away from them and means that I don’t touch them at all.
After removing the caterpillars, squash them with your foot, feed them to chickens or move them to an area of your yard far away from your brassicas.
3. Spray them off with a hose
Another way to remove green worms from your brassicas is to spray them off with your hose. Attach sprayer nozzle that has a jet function and quickly spray the leaves. Short, sharp sprays will dislodge the caterpillars flicking them onto the ground.
Follow up by finding and squishing the caterpillars or give them to your chickens. This will naturally remove them from your yard is completely natural.
4. Bacillus thuringiensis (Bt)
Bacillus thuringiensis (Bt) can be used to treat caterpillars on your broccoli and cauliflower. Bt is a species of bacteria that naturally lives in soil and makes proteins that are toxic to some insects when eaten, including caterpillars.
This is sold as a spray that can be diluted and sprayed onto your broccoli and cauliflower plants. It will get rid of the caterpillars over the next few days. Repeat the treatment until the caterpillars are gone.
For more on how to deal with green worms on broccoli and cauliflower, check out this video below.
How to prevent green worms from attacking broccoli and cauliflower
Here are the best ways to prevent green worms from attaching your broccoli and cauliflower. These tips are easy and can help to protect your brassicas from these destructive bugs.
Grow them in nutrient rich soil
Broccoli that are grown in nutrient rich, free draining soil will be more resistant to pest attack. Cabbage white butterflies can deter the chemical signals of a distressed plant and are more likely to lay their eggs on the leaves.
Build up the soil with aged cow manure and compost before planting. Feed them with pelleted chicken manure every 4 weeks during the main growing season and then slow down as the heads of the broccoli or cauliflower start to form.
Distract the bugs by interplanting
To prevent your broccoli from cabbage white butterfly which will lay their eggs on the leaves hatching green worms, interplant brassicas with other plants. Alternate plants and rows with other vegetables, flowers and herbs to confuse the cabbage white butterfly.
Check your plants daily
The best way to protect your plants from being eaten by green worms is to check them each day. If you catch the problem early you can remove the caterpillars before they spend the day and night eating your plants.
If they are caught early the caterpillars can be picked or squirted off and won’t get the opportunity to eat through your plants. For me it was too late and in 2 days these caterpillars were able to almost eat my broccoli plant entirely.
How to Remove Green Worms from Broccoli and Cauliflower | Summary
Green worms can be very destructive to new and advanced cauliflower and broccoli plants. They can eat young seedlings overnight and take a good chunk of green out of mature leaves. They will eat down to the leaf veins and then eventually eat through them.
Remove green worms naturally by removing them with gloved hands, squirting them off with a hose or by using Bt bacterial treatments. This will help to save your plant from being eaten by the destructive caterpillars.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.