Why Do Seedling Leaves Curl? Reasons And Methods Of Struggle

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Why Do Seedling Leaves Curl? Reasons And Methods Of Struggle
Why Do Seedling Leaves Curl? Reasons And Methods Of Struggle

Every summer resident knows how offensive it can be when, with great care, the sown seedlings, with friendly shoots, sprouted and started to grow, and then for no reason the leaves of the plants began to curl, turn yellow and fall off. This phenomenon is very frustrating for beginners, but not for experienced gardeners. Indeed, in fact, “out of nowhere,” does not happen. There are not many reasons why the leaf blades of seedlings can begin to curl. In this article we will tell you why this happens to our seedlings and how to deal with it.

Twisted leaves on pepper seedlings
Twisted leaves on pepper seedlings

The main reasons that lead to curling leaves in seedlings are:

  • Uneven development of the leaf blade;
  • Lack or excess of nitrogen, phosphorus or potassium in the soil;
  • Improper care;
  • Exposure to pests;
  • Influence of various diseases.

Next, we will consider in detail the reasons for the curl of the leaf blades of seedlings, and talk about how to prevent this phenomenon from occurring and what to do if the leaves have already curled up.

Uneven development of the leaf blade

It is more often observed in pepper seedlings, a little less often in other crops. In the event that the central vein of a leaf blade develops much faster than the leaf itself, then ultimately this can lead to twisting or deformation of the leaf blade itself. This phenomenon is often temporary, you can unnecessarily bother the plants and just wait a while. The leaf blade should develop fully over time and turn into a fully developed one.

Lack or excess of nitrogen, phosphorus or potassium in the soil

The seedlings respond especially negatively to the lack of phosphorus and potassium in the soil. With a deficiency of these elements in the soil, the leaf blades of seedlings can begin to deform, curl and, as a result, become lethargic, as if losing turgor from lack of moisture.

Often there is also a change in the color of the leaf blades of seedlings, they can become lighter or, on the contrary, acquire a black and purple hue. An excessive amount of fertilizer in the soil also does not bode well; this phenomenon can also lead to twisting of the leaf blades of the seedlings.

Prevention and control measures

So, both lack and excess of fertilizers in the soil can negatively affect the seedlings. To understand what exactly the fertilizer is causing the leaves to curl, you must first assess the moisture content of the soil, then examine the leaf blades well for punctures from sucking pests or spots caused by fungal infections. And if you do not find either one or the other, then with a high degree of probability the reason for this phenomenon lies in the amount of fertilizers in the soil.

Excessive amounts of them are quite rare. In this case, you need to transplant the plants into normal soil, free from excess fertilizers, but the lack of fertilizers in the soil can be eliminated more easily by applying them.

Immediately, we note that seedlings, in most cases, do not have enough potassium. The deficiency of this element also causes twisting of the leaf blades. Potassium deficiency can be eliminated by adding potassium sulfate dissolved in water in an amount of 8-10 g per bucket of 50-100 g of solution for each plant or by adding wood ash, which contains about 5% potassium in its composition, as well as a number of seedlings important for the normal development of microelements.

To apply wood ash, you first need to loosen the soil very carefully, then moisten it (preferably from a spray bottle - for uniformity), and then sprinkle with a layer of wood ash 2-3 mm thick.

Improper care

This is a complex, multi-component reason, it includes a lack of lighting, and an excess or lack of moisture in the soil, and the wrong growing temperature. All these reasons can lead to the fact that the leaf blades of seedling plants curl, and with prolonged improper care, the seedlings may die.

Watering seedlings is an important element of care
Watering seedlings is an important element of care

Prevention and control measures

As for watering, the soil must be kept in a slightly moist state, avoiding excessive drying out or excessive waterlogging of the earthy coma. You can understand that the soil is waterlogged if you see that the leaves on the seedlings are twisted up, and the leaves react to the lack of moisture by losing turgor and twisting the leaf blades down.

If there is a lack of moisture, the plants should be watered as soon as possible, if there is an excess, it is necessary to increase the temperature in the room by 4-5 ° C, stop for the duration of watering and loosen the soil daily, forcing excess moisture to evaporate.

Lighting also plays an important role in the life of plants, so you need to try to provide the seedlings with additional lighting for an average of a couple of hours in the morning and evening, and during cloudy weather during the day.

The temperature should not be too high or low, usually after sowing the seeds, they try to maintain the temperature at + 24 … + 25 ° С, after the emergence of seedlings (so that the seedlings do not stretch out, but get stronger) it can be reduced to + 16 … 18 ° С, but a week later - raise again to + 21 … + 22 ° С. At the same time, it is advisable to lower the temperature in the room where the seedlings are grown by a couple of degrees at night.

Exposure to pests

Often, seedlings, even those grown at home, are attacked by pests. Aphids and spider mites can often be found on seedlings. These individuals are practically universal and affect the vast majority of crops grown through seedlings, and they can cause harm already in the early stages of development of seedling plants.

Since both aphids and spider mites are sucking pests, the first thing that can be seen on the leaf blades is reddish specks at the puncture sites of the leaf, then the leaf loses its turgor and curls. If aphids can be easily noticed with the naked eye, then a spider mite is not so easy to notice, most often it lives on the lower side of the leaf.

Aphids on the leaves of tomato seedlings
Aphids on the leaves of tomato seedlings

When turning the leaf blade, you can see a cobweb, these are traces of the vital activity of this pest. When it is found, there is no doubt that the plant is infected with a kidney mite. In case of severe damage to the leaf blades of seedlings, in addition to twisting the leaves, they can completely turn yellow and fall off.

Prevention and control measures

Pests can not only lead to twisting of the leaf blades, but also cause complete or partial death of seedlings, so they must be dealt with very actively. When growing seedlings at home, using "chemistry" is undesirable, it is better to use folk remedies.

So, tincture of onion peel can help to overcome aphids and spider mites, for which you need to pour a glass of onion peel with a liter of boiling water and let it brew for a day. Then the solution must be filtered and every 3-4 days treated with plants until the pests disappear.

You can additionally process the soil, for which it is necessary to prepare a pinkish, weak, potassium permanganate solution. Watering with such a solution should be carried out if the treatment with onion peels did not work. Use the solution carefully, no more than once a week.

Influence of various diseases

Most often, it is a fungal infection, which can manifest itself with excessive soil and air humidity and low temperatures in the room where the seedlings are grown. The infection manifests itself in different ways, but usually it is the spots on the surface of the leaf, which can change color as the fungus matures and spores form.

The vital activity of the fungal infection leads to the fact that the leaf blades curl, change color, and ultimately dry out and die. A very common fungal infection of seedlings that causes leaf blades to curl is apical rot.

Prevention and control measures

Let's start with prevention - so that the fungal infection does not settle on your seedlings, it is necessary to periodically (every ten days) process the seedlings with 1% Bordeaux liquid, if there are signs of infection, then the seedlings should be treated with 2% Bordeaux liquid every five days …

In addition to Bordeaux liquid, you can use a fairly effective infusion that combines garlic and onions. To prepare it, you need to crush a couple of onion heads and 4-5 cloves of garlic in a container and pour five liters of water at room temperature, let it brew for a day, strain and process the affected plants with the resulting infusion.

Often, a solution of nitrate is used, treating diseased plants with it. To prepare a high-quality solution, it is necessary to dissolve 150 g of nitrate in ten liters of water; this solution from a spray bottle should be used to process the seedlings until they recover once every five days.

It is advisable to combine all treatments with the supply of fresh air to the room, that is, periodically ventilate the room where the seedlings are grown by opening doors and vents.

When picking seedlings that have been affected by a fungal infection, it is necessary to add a mixture of tobacco dust, slaked lime and wood ash to the soil, 5-7 grams of each substance per kilogram of soil.

If the seedlings are slightly affected by a fungal infection, whey can be used, which can be sprayed on the affected leaf blades.

We hope that our tips on preventing and controlling leaf curling will help you grow healthy seedlings and move them safely to your greenhouse or garden. How do you deal with this phenomenon? Share your experience in the comments to the article.