There cabbage is a cream white butterfly with black wing tips. It is infamous in vegetable gardens for the damage it causes on cabbages of all varieties and remedies must be timely if you do not want to lose the harvest. A couple of cabbage caterpillars can puncture to destroy a cabbage leaf in a matter of hours, sparing only the rib.
Cabbage: natural remedies
The first natural remedy against cabbage consists of collecting eggs and caterpillars by hand to get rid of them. The eggs deposited by the cabbage butterflies are yellow in color and are always found on the underside of the cabbage leaves.The caterpillars, which are the real problem, come out of the eggs already after one or two weeks at most.
The phytophagous caterpillars of cabbage they are not all the same. Those of the cabbage greater are light green with black dots, while those of the lesser cabbage they are smaller and pale gray in color. Both are harmful to cabbage plants of all varieties.
When the mechanical removal of eggs and larvae is not enough to combat the cabbage a preparation based on Bacillus thuringiensis. The latter is a bioinsecticide allowed in organic farming which, unlike other products, is perfectly harmless to useful organisms. The recommended variety of Bacillus Thutingiensis is the Kurstaki, which is also the most widespread and easy to find in the products on the market. You can buy it conveniently online, for example here
Agrobacterias based on Bacillus thuringiensis variety Kurstaki
And if that's not enough? Foliar treatments with liquid solutions based on Bacillus thuringiensis they are usually effective against cabbage. They act on the caterpillars by ingestion and are even more effective if a small amount of sugar is added to the solution to make it more palatable (and lethal) to the caterpillars.
A couple of treatments of Bacillus thuringiensis usually they are enough, but if this intervention does not prove to be sufficient, you can switch to pyrethrum. The latter, which is obtained from the flowers of particular species of chrysanthemum and is allowed in organic farming. However, it has the disadvantage of being a broad-spectrum insecticide and also cleaning up useful organisms.