Why do cabbage seedlings stretch and what to do?

Cabbage varieties have a long growing season. To ensure a harvest of healthy heads, they must be grown from seedlings. This is where real challenges await gardeners. Cabbage seedlings are very delicate and capricious. Without the right conditions, they can become thin and stretch excessively. This condition should not be allowed, so it's important to know how to correct the situation and prevent it in the future.

Reasons

In most regions of Russia, the number of warm days per year is insufficient for growing cabbage by sowing seeds directly into the ground. Therefore, it is necessary to grow it from seedlings. This method is optimal, allowing for harvesting within the best agricultural timeframe and with minimal losses.

However, growing cabbage seedlings isn't easy either. If you don't follow the basic rules of growing cabbage, the stems of the seedlings will become very thin and pale, stretching upward in search of light, and ultimately, the cabbage will fail to form heads.

Such distortions in the development of seedlings are undesirable and they usually arise for the following reasons:

• incorrect timing of sowing seeds for seedlings and planting them in garden beds;
• acute shortage of natural light and lack of additional lighting sources;
• violation of temperature conditions during the seedling growing period;
• deficiency of essential nutrients in the soil for seedlings.

Optimal timing for sowing and planting seedlings

It's crucial not to over-plant seedlings in a greenhouse or nursery and to transplant them into garden beds promptly. Planting times are determined by the climate of the growing region and the cabbage variety. Early, mid-season, and late varieties are planted outdoors at different times. This typically occurs from late April to mid-May.

Once you've determined the approximate date for planting the seedlings in their permanent location, it's easy to calculate the optimal sowing date for the seedlings. From sowing to germination takes approximately 7 days, and you'll need to allow about 55 more days for the cabbage seedlings to grow.

It turns out that cabbage seeds should be sown in a nursery two months before the planned planting in your garden or homestead. If you don't plant the seedlings by this age, they will inevitably become leggy. Such planting material has no practical value.

Light mode

Cabbage is a crop with high light requirements. In short-daylight conditions or in low-light conditions, shoots will grow upward, toward the light, their color will fade, and they will become thinner and weaker.

Long daylight hours stimulate seedling growth and head formation. The required daylight hours are 14 hours. Considering that seedlings emerge in early March, natural light will be insufficient. Four hours of supplemental light will be needed for the seedlings in the morning and evening.

Temperature conditions

Cabbage doesn't tolerate heat well, and it absolutely cannot tolerate hot weather. At temperatures above the optimal range, it becomes extremely elongated, collapses, and can even die.

After sowing the seeds, cover the seedling trays with plastic wrap and maintain the room temperature at 19 degrees Celsius. When a few seedlings emerge, remove the plastic wrap and set the temperature at 8-10 degrees Celsius. This temperature regime should be maintained until the first true leaf appears.

During the final stage of growing cabbage seedlings, maintain daytime temperatures between 15 and 18 degrees Celsius and nighttime temperatures between 6 and 8 degrees Celsius. Under these temperature conditions, the seedlings are less likely to stretch.

Nutrition and feeding

Cabbage seedlings have fairly high nutritional requirements. It's important to properly formulate the soil for growing seedlings, which involves mixing together:

• turf soil - 50% of the volume;
• humus -50%.

Add the following ingredients to this mixture per bucket:

• 100 g of well-washed river sand;
• 1 tbsp. wood ash;
• 1 tbsp. l. superphosphate;
• 1 tbsp. chicken manure.

During the process of growing seedlings, they need to be fed at least twice:

• in the phase of 3 true leaves;
• during the picking process.

Top dressing is carried out with the following composition:

• 150 g of wood ash;
• 150 g dry chicken manure;
• 10 liters of water.

Violation of the watering regime

Cabbage leaves have fairly large leaves that evaporate moisture well. Therefore, it's important to water them regularly. However, the seedlings will likely stretch out both if the soil is too dry and if it's too moist. Stems grow quickly at soil moisture levels of 85-90%, especially if the temperature is also too high.

Seedlings also stretch excessively when watering begins before germination, as well as up to five days after germination. Watering should begin six days after germination, and be done once every five days.

Sowing density

Some vegetable growers, wanting to get more seedling roots per unit area, place too many plants per square meter. This approach forces the seedlings to compete with each other and, seeking more light, will cause them to stretch. Crowded seedlings require thinning, and this should begin no later than the fourth true leaf appears.

Compliance with these conditions will prevent the seedlings from stretching out.

Signs

Elongated seedlings present a pitiful sight—they're too tall, with thin, pale stems, lying on the ground and failing to form true leaves. And those leaves that do form are small and appear unviable.

Once planted in the garden, such seedlings suffer from prolonged illness and have difficulty recovering. As a result, they produce heads of cabbage 30 days late, and the resulting heads are often of poor quality. Therefore, this condition should not be allowed to develop.

For beginning gardeners, here are the qualitative characteristics of healthy seedlings—the way they should be:

• have a stem with a diameter of 0.8 - 1 cm;
• the distance from the lower pair of leaves to the root collar should be from 3 to 6 cm;
• the height of seedlings before planting is from 15 to 20 cm;
• the plant should have 5 to 7 true leaves;
• the leaves should be green, juicy, smooth, without speckles or dried edges;
• The stem should be straight, elastic and free from curvatures, thickenings and spots.

Effective treatment methods

We've previously noted that seedlings can become elongated for various reasons related to improper cultivation practices. Depending on the cause, appropriate measures must be taken to correct the unfavorable situation.

Supplementary lighting

If the seedlings have stretched out due to insufficient lighting, it is necessary to immediately install additional lighting to ensure up to 16 hours of daylight per day.

Supplemental lighting is necessary not only in the morning and evening hours, but also throughout the day if the sky is overcast. For crops, not only the length of daylight hours is important, but also the lighting intensity.

Temperature drop

If your plants have stretched due to high temperatures, you need to create conditions that are typical for temperature shock. To do this, place the seedling trays in a room where the temperature does not exceed 4°C (39°F) for 5 days. After this period, raise the temperature to 10°C (50°F) and keep the seedlings in these conditions for another 10 days.

The seedling boxes are then returned to their original location and grown for 10 days at a temperature of 15 degrees Celsius. The temperature is then maintained at 20 degrees Celsius during the day and only 9 degrees Celsius at night.

Restoring the correct watering regime

If you notice that your seedlings are stretching due to excess moisture in the soil, you need to stop watering for 3 days.

Before resuming watering, do not wait until the soil is completely dry, as the roots may die due to soil drought.

Next, water the soil approximately every four days, wetting the soil to a depth of 6 mm. Irrigation water should be clean, settled, and at a temperature of 20 degrees Celsius.

Optimizing your diet

If you neglected to apply fertilizers or did not apply enough when preparing the nutrient mixture for seedlings, the seedlings could have stretched out due to poor soil.

Seedlings grown in such soils typically have small, pale leaves. Their stems may also have a modified appearance—they become thin and stiff.

Approximate fertilizer composition:

• potassium chloride - 1 g;
• ammonium nitrate - 2.5 g;
• superphosphate - 4 g;
• water - 1 l.

If there's too much fertilizer in the soil, the cabbage stem will also stretch, and the leaves will enlarge and turn dark green. In this case, stop all fertilizing and flush the soil with generous watering.

Treatment with growth regulators

When seedlings begin to stretch at the stage of first true leaf formation, the use of growth regulators can help stop this negative process:

• "Amulet";
• "Athlete".

These drugs can be used both for the prevention of stretching and for treatment when the first symptoms of this phenomenon are detected.

Growth regulators can be applied by foliar spraying or by watering at the roots of plants. After treatment, root growth accelerates, while vegetative growth is inhibited.

Picking

If the seedlings are severely stretched, the previous measures are unlikely to help. In this case, the seedlings need to be replanted immediately. Here's where to move them:

• in a separate small container if they grew in a seedling box;
• in a spacious container if they grew in shallow cups;
• to the garden bed, if the weather and age of the seedlings permit.

When transplanting, seedlings are planted deep down to the cotyledon leaves. If the seedlings don't yet have true leaves and are very elongated, they should also be pricked out, but not planted so deep.

Removing several leaves

When seedlings are grown in separate, spacious containers and have become elongated, you can remove a couple of the lower leaves. This procedure slows the seedlings' growth and strengthens their roots. If the effect is insufficient, repeat the procedure a week later.

Adding soil

If the boxes containing the stretched seedlings have extra height, add soil to the stems. This approach can be just as effective as pricking out the stems.

You can use a sprinkling method to raise the soil level to the bottom pair of leaves. This will encourage additional root growth.

Forming a loop

If the stem has grown too long, bury it by twisting it into a loop. To do this, reduce watering to a minimum for a while and lower the temperature to 5 degrees Celsius.

This action causes the stem to become limp and can be curled into a ring in the hole. The curled stem is covered with soil, then the soil is compacted and watered.

After rehabilitation measures on the elongated seedlings, if success is achieved and they have stopped growing vigorously, they are provided with the same care as ordinary seedlings, strictly adhering to all requirements.

Re-sowing seeds

Sometimes seedlings become so overgrown that any measures to rehabilitate them seem pointless and doomed to failure. In this situation, the best option is to discard the overgrown seedlings and replant the seeds in the freed-up area.

In this case, the heads will likely appear later than usual, but they will be of better quality than those grown from damaged, elongated seedlings. And it's not a given that they would have grown at all.

Resistant varieties

Among the popular cabbage varieties, the following have relative resistance to seedling elongation:

1. Globe Master F1. Belongs to the mid-season group of varieties, with a growing season of approximately 80 days. The head is dense and round, weighing approximately 3 kg. The heads do not crack. Suitable for salads and processing.
2. June. One of the most popular early varieties. It takes almost 70 days from planting to harvesting. The heads are small and compact, weighing up to 2.5 kg. It is used exclusively for salads.
3. Lika. A popular late-ripening variety. The growing season is 150 days. The heads are round and flat, light green, and heavy, weighing up to 4.5 kg. It has excellent flavor, the heads do not crack, and they withstand transportation and storage well.
4. Present. An old, mid-season variety bred in Russia. The growing season lasts 120 days. The heads are round and whitish, reaching 4 kg in weight. It is used for salads, pickling, and short-term storage.
5. Surprise F1. This early variety produces heads of cabbage, which can be harvested 55 days after planting. The head is round, dense, and weighs up to 1 kg. It is best eaten fresh.

Preventive measures

To prevent cabbage seedlings from stretching, you must initially follow the rules for sowing seeds.

Preparatory work should begin in the fall. Preparing the nutrient mixture for the planned seed sowing is crucial. The ingredients must be properly prepared and mixed in the recommended quantities.

In early spring, bring the soil into a warm nursery, spread it among the seedling trays, and wait a few days for the soil to warm up to the desired temperature. After that, you can begin sowing.

Immediately after germination, to prevent intensive seedling growth and stretching, the room temperature should be sharply reduced to 11 degrees Celsius (52 degrees Fahrenheit). At this lower temperature, the seedlings should grow until the first true leaf appears. Then, the temperature should gradually increase to 18 degrees Celsius (64 degrees Fahrenheit).

To germinate seeds, only the appropriate temperature and humidity are needed. Once the cabbage seedlings emerge, it's essential to provide them with at least 12 hours of daylight. If the seedling tray is located on the north side, it's clear that the plants won't receive enough light. A fluorescent lamp should be installed.

The room where cabbage seedlings are grown should have consistently high humidity. Watering twice a week is sufficient, but it's important not to overwater. If the room temperature rises significantly on a sunny spring day, ventilate the area or move the seedling boxes outside.

Two weeks after germination, transplanting is essential. The day before transplanting the seedlings to a new location where they will have a larger feeding area, water them thoroughly. This will ensure that the transplanting process is minimally damaging to the roots.

At the same time as transplanting, it's advisable to also trim the seedling's main root by one-third. This technique can also curb uncontrolled growth above ground and prevent the seedlings from becoming leggy.

Adviсe

Beginning vegetable growers often puzzle over how to properly plant elongated cabbage seedlings in open ground. These seedlings can also be successfully planted and yield a perfectly good harvest. They are placed in the garden bed when they reach the fourth true leaf stage. Varieties with different ripening times are planted at different times:

• early ripening - in April - May;
• mid-season - in May - early June;
• late-ripening - in May.

Planting in a permanent location is carried out in rows according to the following pattern: 60 by 40 cm. It is recommended to add 150 g of wood ash and rotted manure to each hole during planting and mix these ingredients thoroughly with the soil.

Overgrown cabbage seedlings with long stems and a good root system should be planted. The stem should be twisted into a loop and buried in the hole. Be careful not to damage the roots or stem.

Methods for planting elongated seedlings:

1. If the seedlings are overgrown, plant them at a 45-degree angle. To plant at this angle, you'll need an elongated hole. Don't straighten the curved section of the stem, as it could break. The bottom two leaves can be removed, and the seedling is covered with soil up to the remaining lower leaves.
2. If the seedling's stem is elongated but straight, its root is shortened by a third of its length. The young plant is planted deep down to the leaves, leaving the growth bud above ground level. It's okay if the cotyledon leaves are covered with soil.

During the growth period of elongated seedlings, they are regularly hilled. This agricultural technique promotes the development of additional roots.

Reviews

Gardeners grow cabbage seedlings in different ways, and each has their own method for preventing seedlings from becoming leggy. Read the reviews from our fellow gardeners.

Vladimir Seliverstov, 48 years old, Tula region

"For several years, I tried to grow cabbage seedlings in my apartment. It wasn't enjoyable, and it was a lot of work. I had to provide supplemental lighting, take them outside, water them, and feed them. And the results weren't very good. Now I use a simple method. I wait until the soil warms up at my dacha in April, sow the cabbage seeds in the open ground, and cover each plant with the cut-off bottoms of plastic bottles. During the day, when the weather gets hot, I remove the lids and put them back at night. No more problems."

 

Nadezhda Naydenova, 43 years old, Orel

"This year, I sowed cabbage seeds in mid-March. The seedling boxes were kept on the windowsill. After the shoots emerged, I provided additional lighting with grow lights, but due to the excessive heat in my home, the results were disastrous. The seedlings had very thin stems and fell to the ground. I had to throw out all the seedlings and sow them again."

 

Maria Timofeeva, 37 years old, Orenburg

"We built a polycarbonate greenhouse at our dacha. By the end of April, the soil inside is warm enough. During this time, I place seedling trays there, fill them with soil, water them thoroughly, and then sow cabbage seeds. It takes less than a week for the seedlings to emerge. After that, I lower the room temperature to 10 degrees Celsius and maintain these conditions for 10 days. This prevents my seedlings from becoming leggy and keeps them strong and healthy."

https://youtu.be/DN9dHvR46SM

Those who don't want to spend money on cabbage seedlings should definitely learn how to grow their own. Cabbage is a finicky crop, and growing good seedlings is difficult. However, armed with our recommendations and following all the necessary growing techniques, you can definitely end up with strong and healthy seedlings.