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Cabbage is one of the most difficult vegetable crops to grow, especially if you try to grow its seedlings in an ordinary apartment with central heating. Nevertheless, many novice enthusiastic gardeners go for it, tempted by an attractive picture of a delicious head of cabbage on a seed package. But before you can enjoy such a spectacle in your garden, you will have to go through a fair amount of trials. After all, cabbage has many enemies in the form of pests and various diseases. And she is also very demanding on various growth conditions, and usually her requirements do not at all coincide with those that people strive to create for her. Therefore, cabbage seedlings turn yellow in almost everyone – this is almost its normal state under certain conditions. But the same picture is a symptom of dangerous diseases and problems when urgent action is needed. Why and you need to understand everything in order.
Diseases and pests
When yellow leaves appear on cabbage seedlings, first of all, it is necessary to exclude all the most dangerous factors for the plant.
Insects – pests
There are quite a few enemies who want to feast on juicy cabbage leaves. But most of them already appear when planting cabbage in the ground or when growing seedlings directly in the garden.
They are able to migrate to cabbage seedlings from nearby indoor plants.
- aphid quite well visible on the leaves with the naked eye. These are small light green or translucent oval-shaped insects, up to 5 mm in size, living in large numbers on different parts of plants and sucking juice from them.
- spider mite is found on the reverse side of the sheet in the form of small, almost imperceptible cobwebs, sticky secretions and black dots, and the entire surface of the sheet is, as it were, dotted with small light spots. The cabbage leaf soon turns yellow and falls off.
If any insects are found, all plants must first be washed well under running water in the shower, and then sprinkled over wet leaves with a small layer of wood ash. This is usually enough, especially if all other containment conditions are brought back to normal.
In open ground, dusting with ash can be done immediately after planting cabbage seedlings in the ground. This will help save her from cruciferous flea and other insects.
It is better to water all seedlings with a head. This technique also helps prevent some fungal diseases.
Diseases of cabbage
There are quite a few diseases in cabbage, but at the seedling stage, the most common are the black leg and fusarium. In order to protect cabbage from any diseases as much as possible, it was necessary to subject its seeds to special treatment before sowing, since many infections are transmitted by seed. After germination, it is watered with a solution of phytosporin. This is a natural biofungicide that copes well with all cabbage sores. But it is especially good as a preventive measure. If the disease has already manifested itself, then more powerful means are most often needed. But it is easiest to destroy diseased plants so that they do not have time to infect the rest.
- With black leg the stem becomes thinner, darker and the plant quickly dies.
- In fusarium leaves turn yellow and wilt. Unfortunately, these same symptoms can also be indicative of other conditions, so it makes sense to try to correct the situation first. And only if nothing helps, individual affected plants are to be culled.
- There is another most dangerous disease of cabbage – kila. It is absolutely not amenable to treatment, but, fortunately, it is recognized quite simply. Small rounded swellings or nodules appear on the roots of the seedlings. When picking seedlings or planting them in open ground, carefully check the root system of all plants. At the slightest suspicion of quila, discard the plant without any hesitation. This disease is transmitted, as a rule, through the soil, so when it is found, remember where you got this soil from. If it is taken from your site, then before planting any plants, this bed must be shed with a fungicide solution.
Violation of the rules of care
Answering the question: “Why do the leaves of cabbage seedlings turn yellow?”, You need to remember that there are many factors that affect the growth and development of cabbage seedlings.
Incorrect watering
Mistakes made when watering cabbage seedlings are the most common cause of yellowing of its leaves. After all, cabbage under normal circumstances consumes a lot of water and, accordingly, requires abundant watering. Many beginners, having learned about this, out of excess zeal, begin to water it so much and often that the earth turns sour, the roots begin to experience an acute lack of oxygen, and the leaves turn yellow. In the worst case, the roots begin to rot and the plants can become completely sick.
On the other hand, if cabbage seedlings are constantly on a hot windowsill with bright sunlight and the room is rarely ventilated, then it is possible that it will dry out. Therefore, she may need to water two or even three times a day. But in any case, heat and stuffiness are stressful conditions for cabbage, and the leaves may begin to turn yellow and dry.
Light and temperature
Unfortunately, yellowing of leaves in cabbage seedlings can occur from non-compliance with the rules for keeping plants after germination. The fact is that after germination, cabbage seedlings must be provided with a place with a temperature not higher than + 8 ° С – + 10 ° С for 8-12 days. If you leave it in a warm room, then it will stretch out a lot, the roots will not develop, and new leaves will quickly turn yellow due to underdevelopment of the roots. From such seedlings, even if it survives to be transplanted into open ground, it is unlikely that good heads of cabbage will turn out.
Another reason for the yellowing of cabbage leaves may be a lack of light. Cabbage is a very light-loving plant, and it needs bright lighting during the seedling period. With its lack, it will simply stretch out a lot, and then at the stage of formation of the second and third true leaves, they can gradually begin to turn yellow and dry, starting from the bottom of the plant.
To correct the situation, you can try to apply regular treatment with anti-stress drugs, such as Epin-Extra, Zircon, HB-101, but it is better to change the conditions for the development of seedlings.
Top dressing for cabbage
Cabbage usually needs abundant feeding after planting in open ground. But if poor land was used for planting plants, then theoretically the seedlings can turn yellow from a lack of certain nutrients: nitrogen, phosphorus, iron, potassium.
Such foliar feeding works very quickly and the yellowing of the leaves should stop literally within a few days if the cause is a lack of nutrients.
But more often it happens the other way around – nutrient-rich soil was used for planting cabbage. And when trying to feed the seedlings, her leaves begin to turn yellow. Root poisoning occurs with excess fertilizer. In this case, either washing the soil with water, or transplanting seedlings into new soil can help.
Also, yellowing of the leaves of cabbage seedlings can occur from transplanting into soil with an acidic reaction.
In this case, it is necessary to replace the soil, and if this is not possible, then at least add wood ash or lime as a deoxidizer.
Transplant into the ground
There is a situation when the lower leaves of cabbage seedlings will definitely turn yellow – this happens after planting the plants in open ground. When transplanting, part of the roots is damaged, so yellowing of the leaves is inevitable. There is nothing to worry about, the leaves must be carefully cut or cut off and the seedlings should be shed abundantly. After 5-6 days, it will take root in a new place and actively go to form new green leaves.
As you already understood, almost any stressful situation caused by a violation of the rules of care causes yellowing of the leaves of cabbage seedlings, especially in its lower part. Therefore, in such cases, it is necessary, first of all, to figure out what could cause stress in plants, and then take the necessary measures.
