Why cabbage leaves turn yellow and what to do about it

Yellowing and wilting of cabbage leaves reduces the yield and taste of cabbage heads, and sometimes leads to the complete loss of the planted crop. Timely identification and elimination of the causes of such changes, as well as compliance with agrotechnical and preventive techniques in the garden plot will help to avoid this.

Why do problems appear with cabbage leaves and what to do about it?

To save the crop, it is important to identify the cause of yellowing of leaves at the initial stage and take measures to combat this phenomenon.

The leaves are turning yellow

Yellowness on cabbage leaves occurs as a result of the following factors.

The crop lacks water

Cabbage is a moisture-loving plant and needs regular watering without stagnation of water at the roots. Water the plant in several ways: drip, sprinkling, or using a watering can at the root.

If you are away from the site for a long time, organize drip irrigation, which will maintain a sufficient level of soil moisture. To ensure the ovary of the head of cabbage and the juiciness of the leaves in the summer, cabbage is watered every three days, using 2-3 liters of water. In this case, the sprinkling method is used, watering the plants from a hose over the leaf.

Potassium deficiency

This element is important for young cabbage. In addition to the yellowness of the leaves, when there is a deficiency of potassium, their lethargy is noted.

Fix the problem in two ways:

1. Potassium sulfate (10-15 g per sq. m) is scattered between the rows and the soil is watered with a hose.
2. 10-15 g of potassium sulfate is dissolved in 10 liters of water and the resulting solution is watered over the beds.

Consequences of pesticide treatment

This happens when the dosage is exceeded or recommendations on the time of day or air temperature during processing are not followed. To eliminate the consequences of burns, increase the frequency and abundance of watering, remove severely damaged upper leaves, treat them with growth stimulants (Zircon, Epin) and then abandon pesticides.

Burrowing insect pests

Noticing yellowing leaves on cabbage, gardeners dig up one plant and examine its roots and the hole in which it grew. If traces of insects are found, the area is treated with special means.

The crop is threatened by pests such as mole crickets, May beetle larvae, wireworms, and nematodes. They feed on the roots of the plant, which is why it begins to lack nutrients and reacts with yellowness and dryness of the leaves.

Leaf-eating insect pests

The most common are cruciferous flea beetle, aphid, stem weevil, cabbage fly, cabbage fly. In this case, in addition to the yellow color of the leaves, punctures, bites and gnawed passages are visible on their surface. The plant is stressed and tries to get rid of damaged parts.

It is better to fight pests before they appear. To do this, the soil for planting is thoroughly cleaned of plant residues from last year’s crops and poured with boiling water to destroy overwintered larvae and eggs. During the season, weeds are regularly removed, and the cabbage is sprayed with a solution based on onion, garlic, wormwood or oregano with the addition of laundry soap for viscosity.

Fusarium

The first sign is the appearance of yellow spots, then the leaves and stem curl, darken and break.. Fusarium pathogens live in the soil for 5-6 years, so gardeners recommend planting cabbage in different areas each time, and carrying out disinfection procedures before sowing seeds (in the ground or for seedlings). To do this, the seeds are soaked for several hours in a weak solution of potassium permanganate, and a small amount of wood ash is poured into the holes.

There are also varieties resistant to this disease. If cabbage on your site has already died from fusarium blight, choose a variety with strong immunity.

Cauliflower leaves drying out

The causes of leaf damage in cauliflower and white cabbage differ little. Correct watering and timely control also play a decisive role here. with diseases and insects.

Water with warm water every two to three days in temperate climates and daily in hot, dry regions. Consumes up to 10 liters of water per square meter. m. Water cauliflower in the morning or evening, when the sun is no longer so active and allows moisture to be absorbed without evaporating it.

Cauliflower leaves suffer from clubroot, fusarium and white rot. Vascular bacteriosis is also dangerous, which leads to to change the color of the leaves to purple with yellowing towards the center. Gradually the leaf curls, dries out and breaks. Most often, vascular bacteriosis is infected by insects, so effective preventive measures to combat them will protect your harvest.

White cabbage leaves wither

A disease called clubroot causes yellowing and wilting of leaves. Cabbage affected by it differs from healthy plants in growths on the roots. Because of them, the nutrition of the plant is disrupted and the process of leaf dying begins.

Diseased samples are dug up and destroyed; they can no longer be saved, and the soil is treated with a 0.1% Fundazol solution and then sprinkled with wood ash (500-700 g per sq. m).

Attention. A simple technique helps strengthen the plant’s immunity: before planting in open ground, seedlings should be hardened off by taking them out into the open air. Start with half an hour and gradually increase the time spent outside until full daylight hours.

Why do the leaves of cabbage seedlings turn yellow?

Reasons that cause the leaves of cabbage seedlings to change color from green to yellow:

1. Excess or lack of moisture. Due to the large amount of water, the soil becomes compacted and ceases to allow oxygen to pass through. The roots of the seedlings begin to rot, and the leaves turn yellow and wither. If watering is insufficient, the plant ceases to receive sufficient nutrients, its growth slows down, and the leaves die off.
2. Lack of potassium or iron. If the edge of the leaf turns yellow, the seedlings need additional potassium fertilizer. With a lack of iron, yellowness affects the bottom of the leaves.
3. Bad light. Cabbage is a light-loving plant. You can make sure that the seedlings do not have enough light by looking at the stem - it also changes color to yellow.
4. Temperature changes. When growing cabbage seedlings, maintain a constant temperature of +8...+10°C. If the temperature drops below and lasts for several days, the seedlings die. At higher rates, seedlings begin to grow, the root system cannot cope with the load and new leaves turn yellow.
5. Roots are damaged. For example, during a pick. Or as a result of exposure to insects. Therefore, a handful of wood ash is always added to the soil or watered with a weak solution of ammonia (2-3 drops per 10 liters).

Do not plant seedlings in soil with a high content of sea sand. Salt also leads to yellowing of the leaves; seedlings in such soil will die.

Reference. Before planting seeds, be sure to disinfect them in a weak solution of potassium permanganate or Fitosporin. This will kill fusarium and blackleg pathogens. Both diseases lead to plant death and quickly spread among seedlings.

Prevention measures

To avoid the problem of yellowing cabbage leaves, follow these simple tips:

1. Choose varieties that are adapted to growing in your region and are immune to common diseases and pests.
2. Carry out pre-sowing treatment of seeds, plant strong seedlings in the ground without traces of disease or mechanical damage.
3. Before planting seeds or seedlings, clear the soil of debris and weeds, pour boiling water over it and sprinkle with wood ash.
4. Observe rules of agricultural technology for caring for this crop. Provide proper watering with warm, sun-heated water and regular feeding potassium and phosphorus.
5. When treating plants with insect repellents, follow the instructions. Do not spray solutions at lunchtime to prevent the leaves from getting burned.
6. To combat fusarium, use the drugs “Fundazol”, “Paracelsus”, “Trichodermin”.
7. Leaf-gnawing insects are repelled by “Aktofit”, “Aktara”, “Cabbage Rescuer”, and “Zemlin” and “Bazudin” fight soil pests. To scare away insects from the beds, plant oregano, marigolds, and garlic nearby.

Conclusion

To avoid losing your cabbage harvest, take action immediately after detecting yellow spots on the leaves.Grow varieties adapted to the weather conditions of the region on your site, water the plant regularly and abundantly, fertilize and treat the beds with pest repellents.