by Cabbage head rot is a fairly common problem that many gardeners face. Rotten cabbage becomes unfit for consumption, which leads to crop loss.
For this reason, it is extremely important to quickly determine the cause of the rot and do everything possible to eliminate it.
Lack of light and space
One of the main reasons why cabbage heads start to rot is the wrong place for the bed. Cabbage likes well-lit places – lack of sun and constant shade can cause rot on the heads. The bed should be located in an open area, away from fences, outbuildings and trees that cast shadows on the plants.
Rotting is often caused by dense plantings. If you did not take into account the size of adult plants when planting seedlings and left too little space between the seedlings, after a few months they will begin to suffer from lack of space.
The distance between rows and between rows when planting cabbage depends on its ripening period:
- early varieties: seedlings are placed at a distance of 30 cm from each other – both in rows and between rows;
- mid-season varieties: seedlings are placed at a distance of 45 cm;
- late varieties: the distance between plants should be at least 50-60 cm.
If the plantings are too dense, remove some of the plants – this will improve the illumination of the plants and air circulation in the bed and protect the remaining heads from rotting. Another option is to tear off several lower (largest) leaves from the plants.
Excessive amount of nitrogen fertilizers
As is known, excess nitrogen affects the preservation of fruits: the harvest of many crops, including cabbage, is stored worse. However, an excessive amount of nitrogen fertilizers can lead to another problem – rotting of cabbage heads. For this reason, the main emphasis when growing cabbage should be on potassium and phosphorus fertilizers.
Cabbage is fed several times per season. The first time is two weeks after planting the seedlings: 10 g of superphosphate and 20 g of urea and potassium sulfate are diluted in a 10-liter bucket of water.
2-3 weeks after the first, the second feeding is carried out. This time, nitrophoska (2 tbsp. per 10 l of water) or organic matter (infusion of mullein or bird droppings) is added.
Mid-season and late varieties of cabbage are fed again after 10-14 days. This time, nitrogen is no longer used – superphosphate (10 tbsp) dissolved in 2 l of water and fertilizer with microelements (15 g) are added.
In addition, before planting seedlings, add a handful of wood ash to each hole. It is not only a source of potassium, phosphorus and two dozen other useful elements, but also a means that will help deoxidize the soil and prevent the appearance of the most dangerous cabbage disease – clubroot.
Excess moisture
Cabbage is a moisture-loving crop. It consists of 92% water, so water is vital for the plant: if there is a lack of moisture, the formation of heads of cabbage will be slowed down, and the heads that have already formed will grow small. However, an excessive amount of moisture also has a negative effect on the harvest: the heads of cabbage begin to rot or crack.
In rainy weather, cabbage is not watered, because the crop has enough natural moisture. When the weather is hot and dry, the plants are watered regularly, at least once a week, using 1-13 liters of water per 15 sq.m.
If there are heavy rains, the cabbage bed will have to be protected not from a lack of water, but from an excessive amount of water. To do this, build a temporary shelter over the plantings: put up arcs and stretch a film.
Don’t forget to regularly loosen the soil. After that, the moisture will evaporate more actively, which will help save the roots from rotting. Another way to help cabbage damaged by prolonged rains is to remove weeds. They do not allow excess moisture to evaporate, so they can also cause rot.
Cabbage diseases
Diseases can also cause rotten leaves on cabbage heads, most often this is slimy bacteriosis (wet bacterial rot).
Usually the first signs of the disease appear towards the end of summer. The development of slimy bacteriosis is promoted by warm rainy weather, leading to excess moisture in the soil.
The bracts affected by bacteria become covered with dark oily spots that gradually increase in size. After some time, the leaf blades darken completely and rot. The stalk softens, and an unpleasant putrid smell comes from the head. Sometimes the external signs of the disease do not manifest themselves in any way, and only after cutting can rot be seen inside the head.
If you managed to detect the mucous bacteriosis at the earliest stage, when only a few leaves are affected, then the head of cabbage can still be used. To do this, remove the affected leaves and a few healthy ones, and try to eat the rest as quickly as possible, and only after heat treatment.
If rot is found inside the head of cabbage, it can no longer be used for cooking. Remove the diseased plant from the garden bed, take it outside the plot and burn it. Dig up the place where the rotted cabbage grew and cover it with wood ash or quicklime, or pour generously with Fitosporin-M (dilute according to the instructions). Such measures will help save the heads of cabbage remaining in the garden bed.
There are no methods for treating mucous bacteriosis. Only compliance with preventive measures and rules for growing cabbage will help protect cabbage plantings from this disease.
Cabbage pests
Pests can also be an indirect cause of cabbage head rotting. They damage cabbage leaves, which leads to infections. And this, in turn, can cause cabbage heads to rot.
The greatest danger to plants of the Cruciferae family, including cabbage, is the cruciferous flea beetle. Insects gnaw holes in the leaves, which is why cabbage leaves look perforated. Flea beetle larvae eat thin roots, disrupting the development of plants. During rains, all sorts of diseases begin to develop on damaged plants, leading, among other things, to rotting of heads of cabbage.
To prevent the appearance of the cruciferous flea beetle, plant plants around the perimeter of the cabbage beds that will repel the pest with their smell: marigolds, calendula, coriander, nasturtium, caraway, etc. Water the cabbage regularly (the flea beetle does not like moisture), feed it and loosen the soil around the heads of cabbage. After each watering, dust them with wood ash. For better adhesion to the leaves, spray the cabbage with a solution of green soap before dusting.
Planting cabbage varieties and hybrids that are resistant to the main diseases of cruciferous plants will also help to avoid rotting of heads of cabbage in the garden: Airbus F1, Snow White, Galaxy F1, Cossack F1, Kolobok F1, Mara, Paradox F1, Gift, Extra F1 and more.
