Contents
Petunia is an amazing flower designed to decorate garden beds and balconies. The South American plant has perfectly “taken root” in Our Country and has been popular with beginners and experienced flower growers for many years now. Petunia is grown mainly in seedlings in order to speed up the flowering process. However, unfortunately, sometimes problems can arise in growing seedlings of petunias. The most common problem is yellowing of the leaves. But why does petunia seedlings turn yellow, what could be the reasons for this and how to correct the situation? The answer to these and some other questions can be found in the article below.
Reasons why petunia seedlings turn yellow
Excess moisture
When yellow, brittle leaves appear on petunia seedlings, you should think about whether the plant roots suffer from excessive moisture. So, the most common cause of yellowness is root rot. Petunia roots, being constantly in an environment with high humidity, experience oxygen starvation, stop developing and absorbing nutrients from the soil. As a result of such an anomaly, the leaves of petunias turn yellow and eventually fall off.
The root cause of excessive accumulation of moisture may be the lack of drainage or frequent watering of plants. In this case, you can correct the situation and save petunias. To do this, drainage holes should be made in the bottom of the container with seedlings and yellow leaves should be removed from the plants. With severe decay, petunias should be transplanted into fresh, well-drained soil, before treating the roots with an antifungal drug.
Lack of nutrients
For growing seedlings of petunias, it is necessary to use soil saturated with nutrients. You can buy it or cook it yourself by mixing garden soil with peat and sand. Also in the process of growing seedlings of petunias must be fed. Otherwise, as the flower seedlings grow, they may lack useful trace elements. Especially for petunia, substances such as iron, sulfur, zinc and magnesium are important:
- With a lack of iron, petunia leaves turn yellow, but the green color of the veins on the leaves remains. Such symptoms indicate the development of chlorosis. You can replenish the amount of iron in the soil by using the preparations “Cytofit”, “Ferrovit”.
- A yellow leaf plate of a petunia, with twisted dry edges, indicates a lack of magnesium. This trace element can be replenished by using magnesium sulfate.
- Zinc deficiency manifests itself in the form of small yellow blotches on the leaf. Over time, yellowness covers the entire leaf plate, which leads to its death. For the treatment of seedlings in this case, it is recommended to use zinc sulfate.
- In the case when the yellow leaves of petunia seedlings become red over time, it is worth talking about an insufficient amount of sulfur in the soil. You can add the missing trace element by sprinkling the soil with grated sulfur.
When there are signs of a lack of one or another microelement, complex fertilizers can also be used. They contain all the necessary minerals and will become a source of healthy nutrition and enhanced seedling growth. For fertilizing plants, it is recommended to alternate root and foliar feeding.
vermin
Insects can be another cause of yellow petunia leaves. Despite the fact that the seedlings are indoors, they can be parasitized by:
- spider mite. This small-sized insect has a red color and “prefers” conditions for life with high soil moisture and low air humidity, which is quite typical for petunia seedlings. The spider mite is adapted to home conditions and open ground. The presence of this pest is evidenced by the entangling web on the leaves, their yellow color and the slow growth of seedlings. You can defeat the tick by treating the leaves with soapy water. Also, in the fight against the pest, crushed sulfur powder and special chemicals are used that can be safely used at home.
- aphid – Another pest that is well known to all gardeners and flower growers. These small insects settle on the underside of the leaf and are often invisible to the eye until there are serious problems with the plant. The aphid feeds on the cell sap of the leaves, causing them to turn yellow and curl up before drying out. It is rather difficult to fight aphids on seedlings, and, probably, with large areas of infection, plants are easier to destroy than to process. However, especially painstaking flower growers suggest using a solution prepared from soapy water and nicotine sulfate (1 g of substance per 1 liter of soap solution). The resulting product should be sprayed with seedlings and wrap it for a day in a plastic bag. After the prescribed processing time, the seedlings are washed with clean water.
- whitefly – a frequent guest of glazed balconies, loggias and greenhouses. This insect looks like a small, bright butterfly. As a rule, her fluttering over the petunia ends with the appearance of white pigment spots, and then yellowness on the leaves. Soon, such leaves curl and fall off, the plant dies. In addition to direct harm to plants, the whitefly can become a source of fungal diseases, the spores of which it carries. In the fight against pests, only special preparations are used.
When growing seedlings of petunias, it is worth remembering that it is much easier to deal with a pest in the initial stages of damage. Untimely detection or lack of measures to prevent the harmful effects of pests on seedlings leads to the inevitable death of petunias. You can learn more about pest control methods for seedlings at home in their video:
disease
The reason that the foliage of petunias turned yellow may be a fungal disease – powdery mildew. This disease rarely affects plants growing in protected conditions, however, untreated soil containing spores of this fungal disease can become its source. Spores are often dormant and are activated by sudden changes in temperature and humidity. Excessive application of nitrogen-containing baits can also provoke the development of this disease.
Powdery mildew appears in the form of a dense white coating that covers the leaves of petunias. As a result of such exposure, the seedlings lose their elasticity and become lethargic. The leaves under the veil of plaque become yellow, and then brown.
You can rid the seedlings of the disease by treating with “Fitosporin”, “Topaz”. Before treatment with these substances, the damaged parts of the seedlings should be removed and, if possible, burned. Adult petunias infected with powdery mildew are transplanted into new soil and a disinfected pot.
Conclusion
In order to avoid all of the above troubles, you should carefully monitor the seedlings of petunias. For watering plants, it is better to use soft, settled water. You can also soften it by adding a little lemon juice. Regularly (1 time in 2 weeks), young petunias should be fed with complex fertilizers, which will allow the seedlings to develop harmoniously. If pests are found, measures should be taken as soon as possible to destroy them, otherwise the seedlings will become a source of food and a prosperous existence for them. So, only an attentive, caring owner will receive healthy, strong seedlings of petunias as a reward for his work, which will decorate flower beds and planters with bright, beautiful flowers.