Protecting Brassicas, Peas, and Beans from Caterpillar Damage

Few things are more frustrating than tending lovingly to your veg patch only to discover leaves stripped to lace by caterpillars overnight. Brassicas, peas, and beans are prime targets for these hungry larvae, especially during the warmer months when eggs hatch fast and feeding frenzies begin. But don’t panic, we’ve got a solid plan for protecting brassicas, peas, and beans from caterpillar damage, without reaching for the spray bottle.

Know Your Enemy

Caterpillars come in many forms, from the infamous cabbage white butterfly to pea moth larvae and cutworms, but the damage is usually the same: chewed leaves, ruined pods, and weakened plants.

We make it a habit to check the undersides of leaves regularly, especially during peak laying season (late spring to early autumn). Early detection means easier control.

Cover Up Early

Prevention starts with netting. Fine mesh netting or insect-proof mesh is our first line of defence. We use it over hoops to cover brassicas the moment they’re planted out. This keeps adult butterflies and moths from laying eggs on the leaves.

For peas and beans, we’ve had great success with temporary mesh tunnels or floating row covers while plants are young and most vulnerable.

Hand Pick

It may not be glamorous, but hand-picking caterpillars works. Do a quick daily patrol of our plants, removing caterpillars and eggs before they can do major damage. A bucket of soapy water nearby makes disposal easy and effective.

With regular checking, you can keep populations under control without much effort.

Encourage Natural Predators

Birds, frogs, wasps, and beetles all love a juicy caterpillar snack. We make our garden a haven for beneficial wildlife by including bug hotels, bird feeders, and water sources. A biodiverse garden is a resilient garden.

Ladybird larvae and parasitic wasps are especially good at controlling eggs and tiny caterpillars before they get out of hand.

Plant a Decoy or Trap Crop

Some growers swear by using nasturtiums or sacrificial brassicas to lure cabbage whites away from the main crop. We’ve used this tactic with success, especially around the edges of raised beds. It doesn’t stop them all, but it reduces pressure on your main veg patch.

Just be sure to check your decoys regularly and remove caterpillars before they move on.

Feed for Resilience

Healthy, vigorous plants are better able to withstand a bit of nibbling. We feed our brassicas, peas, and beans with seaweed feed or compost tea to boost their strength and resilience. Balanced nutrition helps them grow fast enough to outpace minor pest damage and bounce back from bigger attacks.

Try Natural Sprays if Needed

As a last resort, we sometimes use homemade garlic or neem oil sprays to deter caterpillars. These should be applied in the early morning or evening, and never when beneficial insects are active. They’re not magic bullets, but they can slow down infestations when used with other methods.

Caterpillars are persistent, but so are we. By combining physical barriers, regular checks, wildlife support, and plant care, we can protect our brassicas, peas, and beans from caterpillar damage and grow strong, leafy crops without holes or heartache.