Content
Flower growers often notice that the leaves of petunia seedlings curl. However, their color does not change. This is a sign that the plant is experiencing stress. It is necessary to establish the causes as soon as possible and take urgent measures.
Why do petunia seedlings' leaves curl?
There are several factors that cause this phenomenon - non-compliance with the rules and various diseases. The fact is that petunia seeds are sown very early - in January or February. This is not the most favorable time for growing seedlings in a city apartment. Winter is characterized by short daylight hours. In addition, during the heating season, the air in apartments has low humidity - less than 50%.
Insufficient lighting
Even on south-facing window sills there is little light for seedlings at this time of year. For its full growth and development, the duration of the light period must be at least 10 hours a day. When there is insufficient light, the leaves of petunia seedlings curl down. The situation is aggravated if they use places far from the window for growing.Cloudy winter days make the situation worse, when even during daylight hours there is insufficient lighting.
To prevent the leaves of petunia seedlings from curling, you can place wide bowls of water nearby.
Insufficient air humidity
Low indoor humidity can cause petunia leaves to curl. It is known that hot batteries significantly reduce the humidity of the surrounding air. Since the heating season is in full swing in winter, the lack of moisture in the air has a detrimental effect on young plants.
Violation of water regime
Curling of leaves is observed when watering conditions are violated. The cause of this phenomenon can be either an excess of moisture or a lack of it. Seedlings are watered every 2-4 days. The signal to replenish moisture is the drying out of the top layer of soil. Take settled water at room temperature. Moisten the soil, trying to prevent water from getting on the leaves and stems. Excessive watering is detrimental to the plant. If the soil moisture is high, the seedling runs the risk of dying from blackleg.
Excessive irrigation after a drought is especially dangerous. If for some reason the plant has not been watered for several days and the earthen ball has dried out, the soil should be moistened in small portions, gradually restoring the optimal water regime.
Excess nitrogen in the soil
Nitrogen affects the increase in green mass. If there is too much of it in the soil for seedlings, the leaves will develop intensively. The vein located in the center lags somewhat behind. Over time, the leaves become uneven, the edges begin to turn up, down or to the sides.
Lack of microelements
It has been noticed that with calcium deficiency, the leaves of young petunias curl upward, and with phosphorus starvation, sulfur or boron deficiency, they curl downward. If there is not enough copper, the side edges of the sheet are folded down.
Viral diseases
The most dangerous cause is viral infections. Infection can occur through soil or seeds. Seedlings can be infected by tobacco and cucumber mosaic viruses. At the first disease, the edge of the leaf blade curls upward, becomes covered with necrotic whitish or gray spots and streaks, and gradually dries out. During the second infection, waviness appears along the edge of the leaf and yellowish spots form on it. Infection with viruses can contribute to the death of seedlings.
Do not spray petunia with water, the plant does not tolerate moisture on the leaves and stems
Aphid
Aphids settle on young plants, feeding on their juices. Insects are located on the tips of shoots and leaves. A light transparent sticky coating is found on their surface. These are insect secretions. Gradually, the affected leaves curl, become deformed and die.
Aphids on petunia seedlings need to be treated with insecticides
What to do if petunia leaves curl
After identifying the reasons, measures are taken aimed at normalizing the conditions for growing seedlings.
The lack of sunlight is compensated by artificial lighting. Purchase phytolamps or use regular fluorescent lamps. They are placed at a distance of 60-80 cm from the seedlings.
Do not place lamps too close to plants. This can lead to overheating of the seedlings.
To prevent curling of petunia leaves, it is necessary to install artificial lighting until mid-March.
You can increase indoor air humidity in the following ways:
- put a humidifier in the room;
- reduce the temperature of heating devices;
- place water in open containers next to the seedlings;
- hang a curtain of plastic film between the battery and the seedlings and moisten it regularly;
- pour pebbles into the tray and make sure they are constantly wet;
- cover heating devices with a wet sheet.
If the curling of seedling leaves is caused by an excess of nitrogen and a lack of microelements, they try to adjust the composition of the soil by adding the missing components. Every 10 days, plants are fed with monofertilizers or complex mineral compounds without nitrogen.
If signs of viral diseases are detected, the plant cannot be treated. To avoid infecting the rest of the seedlings, it is dug up and thrown away as quickly as possible. The earth is disinfected with a solution of potassium permanganate.
When aphids appear, seedlings are sprayed with solutions of insecticides - Intavir, Fufanon, Iskra, Aktara. If there are a lot of insects, the treatment is performed 2-3 times every 10 days.
If there are children or pets in the family, chemicals are stored and used in compliance with the necessary safety measures.
Petunia seedlings need to be watered when the top layer of the substrate dries out.
Prevention
Preventive measures begin at the stage of preparing the soil for seedlings and seed material.
For the soil, prepare a mixture from garden soil, adding peat and sand to it. Fresh manure is not used. It contains a lot of nitrogen. You can add perlite or vermiculite and mustard cake. This will make the soil more loose and moisture-permeable.
To remove viruses and fungal spores, the soil is steamed in the oven or poured with boiling water.
Before sowing, seeds are pickled in a solution of potassium permanganate, Fitosporin or the drug Maxim.
A drainage layer is placed at the bottom of the seedling container, and only after it is soil poured. This prevents the seedlings from becoming waterlogged.
Boxes with seedlings are placed on the brightest window. After the seeds have sprouted, they try to provide artificial supplementary lighting.
They also monitor air humidity, taking timely measures to increase it. Observe the regime of watering seedlings. Provide timely feeding of plants with complex fertilizers containing the necessary microelements.
Conclusion
Having discovered that the leaves of petunia seedlings are curling, experienced gardeners find out the cause and take urgent measures to eliminate it. Proper agricultural technology and timely disease prevention are the key to strong, healthy seedlings and future lush flowering.
