The cabbage grower's nightmare - cabbage butterflies, cabbage moths, and cabbage flies

It's not just us humans who appreciate cabbage - unfortunately, it's also a favorite of many insects. Cabbage white, predatory butterfly, rape butterfly, and cabbage fly are some of them that gladly munch on the leaves. To win the battle for the crops, they must be fought early and aggressively. Here are the tricks that help.

The cabbage butterfly and its larvae, known as cabbage worms, are the cabbage grower's nightmare. They feed on nearly all cruciferous plants within the cabbage family, such as broccoli, cauliflower, and Brussels sprouts. Additionally, the butterflies can produce two to three generations in one year, resulting in large numbers of larvae – which can easily devour an entire plant given enough time. Cabbage white butterflies and diamondback moths are also cabbage-loving butterflies that pose a threat to crops. Not only do they feed on the plants – the holes they and cabbage butterflies create can also serve as entry points for various fungal infections.

Cabbage moth causes great damage to cabbage plants. The cabbage moth is visually a quite inconspicuous butterfly. Some years it explodes in numbers and can then cause great damage to cabbage plants. Some cabbage varieties can fare better than others, but if they have little food, the cabbage moth also attacks plants they like less such as arugula, watercress, and marigold. Particularly vulnerable are broccoli, cauliflower, and Brussels sprouts. Signs of cabbage moth are black spots (feces) on the foliage and transparent spots on the leaves. The larvae prefer to sit near the main leaf veins. Sometimes the moth also creates webs on the underside of the leaves. Cabbage moth is easiest to control when the eggs have turned into green centimeter-long larvae – you can often see them hanging in thin strands under the plant.

The small and large cabbage fly, Cabbage flies attack cruciferous plants such as cabbage, rapeseed, oil plants, but also grass. The larvae also feed on roots. Crop rotation is a good, preparatory protection against cabbage flies, in addition to protective barriers around the base of the plants. These can be made from, for example, fresh sawdust, wood ash, or algae meal.

7 tips to counteract attacks from cabbage-loving insects. Give the cabbage plants good conditions - it strengthens their defense. Cabbage thrives with good access to water and nutrients, and prefers relatively cool weather - it prefers clay soil over sandy soil. Cabbages in rainy, cool areas often fare better than those in dry and hot conditions. Water regularly.Grow the cabbage under protective net tunnels or row covers. Cover them from sowing so that no pests can enter and lay eggs. The difference between covered and uncovered plants is significant. Row covers also protect plants from wind and light frost, and reduce water evaporation. Netting also works well, but do not place it too close to the cabbage - insects can lay eggs through the small holes in the net.Inspect and crush. Regularly check under the leaves - both larvae and yellow eggs may hide there. Crush both between your fingers.Grow a variety of plants, making it difficult for pests to find their favorite visually or by scent, and also beneficial for predatory insects that eat them. Buckwheat and dill are popular among many predatory insects and can be sown in flower beds and vegetable gardens.Try old wives' tales. Try intercropping with tomatoes and other strongly scented plants, or spray the cabbage with chili or soap water.Spray with Turex/larval protection. This is a microbiological bacterial powder mixed with water. When the larvae ingest the bacteria, their digestive system is destroyed and they die. The bacterium Bacillus Thuringiensis is naturally present in the soil. The product is approved for organic farming and breaks down by the sun's UV rays after a few days, but is not approved in all Nordic countries. The products do not harm bees, beneficial insects, or mammals, but protective gear should be used as the product can cause irritation.Trim away the damaged parts. The affected plants often recover with a little care like regular watering and a moderate amount of fertilizer.

Liselotte Roll, Swedish garden inspirator, journalist, and author of books on nature, cultivation, and animals, such as "Jord", "Grow for insects", and "Chickens as a hobby".