Cabbage White Butterflies: Why They Can Be A Problem For Your Vegetable Garden And How To Prevent Them From Causing Damage

It’s rare for the caterpillars of most butterfly species to cause harm to your plants and veggies, but the cabbage white butterfly is an exception. Cabbage white caterpillars are called imported cabbage worms and can cause extensive damage to cabbages and other brassicas.

Why Are They A Problem?

If you grow vegetables like cabbage, bok choy, Brussel sprouts, kale, and broccoli, then you’ll want to take extra precautions to make sure that they stay protected- as these are a cabbage worm’s favourite thing to feast on.

When cabbage worms first hatch, they will eat the surface layer of the leaves, leaving behind an opaque scar. Fully grown worms will be able to chew holes in leaves and burrow into the heads of cabbage, leaving behind faecal matter that can contaminate your vegetables.

The bottom line is that pests like cabbage worms are going to cost you money in the long run. The more crops that you have to throw away because of damage, the less produce you’re getting out of each batch. Although there’s no fool-proof way to completely eradicate every pest from your garden, there are some things you can do to prevent and treat the issue.

How Can I Treat The Problem?

If you’re looking for a quick (albeit not so environmentally friendly) fix, then using a chemical pesticide with an ingredient called pyrethrum in it will soon banish white cabbage worms from your plants. Pyrethrins work of exciting the nervous system of insects that touch and eat it, leading to paralysis and death. 

However, not everybody agrees with using synthetic chemicals to tend to their garden. Artificial pesticides, herbicides and fertilisers have been proven to cause damage to the environment and ecosystem, and there’s a risk of consuming some of the chemicals if you don’t thoroughly clean all of your fruit and vegetables. 

If you’re looking for a more organic way to fix your problem, then here are some eco-friendly damage-preventing tips:

Provide A Physical Barrier

Members of the cabbage plant family tend to be bug magnets, but some insect netting will soon sort that problem out. This netting is soft to touch so it won’t damage plants, yet it provides excellent protection from cabbage white butterflies.

Not only is mesh netting better for the environment, but many pests are often better controlled by insect-proof mesh than by chemical pesticides. Mesh netting can also help to keep your plants protected from rain, hail and heavy winds, as well as retaining heat without significant increases in temperature.

Little Fields Farm offer a selection of garden netting in different widths and lengths to suit your needs. One roll of netting can be cut up and used for multiple different plants, saving you money in the long run. Check out their insect or butterfly netting to give you the best treatment and prevention of cabbage worms.

Inspect And Remove

It’s a job that no one takes great pleasure in doing, but by manually removing cabbage worms from your plants, you’re doing your bit to protect your vegetables. Take time to inspect the underside of the plants’ leaves and remove any egg clusters, and be sure to remove any caterpillars you can see by hand.

The best way to do this is to walk from row to row, and follow a clockwise system so that you know that all of your plants have been checked. 

Depending on how badly your plants have been affected, the removal process might be a long one, but it’s an essential first step for keeping your plants protected. Hopefully over time, if you are implementing all the tips in this article, then you should no longer have to manually remove pests from your plants as often. 

Encourage Beneficial Wildlife

Caterpillar consumption is common among birds, and luckily, there are many of your standard backyard birds that eat caterpillars. Some examples include blue tits, great tits, thrushes and robins. To encourage more of these birds into your garden, consider getting a bird feeder, a bird box or a bird bath. The more bird-friendly your garden is, the more likely they are to consider nesting there. 

Any caterpillars that you find on your plants could be placed directly onto your bird feeder so that the birds know what your garden has to offer. Certain shrews and spiders also eat caterpillars, so think twice before you kill that next spider!

Consider Intercropping

Intercropping works by confusing pests, making it more difficult for them to find their host plants. Instead of planting one type of vegetable in a row or a square, you should mix them up among other plants. It’s also a good idea to switch-up where you plant things every so often. Tansy and thyme are reported to repel cabbage worms, so consider planting some among your veggies.