Content
Petunia is an amazing flower designed to decorate garden beds and balconies. The South American plant has taken root well in Russia and has been popular with both beginner and experienced flower growers for many years. Petunia is grown mainly in seedlings, in order to speed up the flowering process. Unfortunately, however, sometimes problems can arise in growing petunia seedlings. The most common nuisance is yellowing of the leaves. But why seedling petunia turns yellow, what could be the reasons and how to fix 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, fragile leaves appear in petunia seedlings, you should think about whether the roots of the plants are suffering from excess 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 absorb nutrients from the soil. As a result of such an anomaly, the leaves of petunias turn yellow and fall off over time.
The root cause of excess moisture accumulation can be lack of drainage or frequent watering of plants. In this case, you can correct the situation and save the 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. In case of severe decay, petunias should be transplanted into a fresh, well-drained primingbefore 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 petunia seedlings need to be fed... Otherwise, as 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, the leaves of petunia turn yellow, but the green color of the veins on the leaves remains. Such symptoms indicate the development of chlorosis. It is possible to replenish the amount of iron in the soil by using the preparations "Cytofit", "Ferrovit".
- The yellow leaf blade of petunia, with curled 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 acquire a red tint 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.
If there are signs of a lack of a particular trace element, you can also use complex fertilizers. They contain all the necessary minerals and will be a source of healthy nutrition and enhanced seedling growth. To fertilize plants, it is recommended to alternate root and foliar fertilization.
Pests
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 insect has a red color and "prefers" for life conditions 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 cobweb on the leaves, their yellow color and slow growth of seedlings. You can defeat the tick by treating the leaves with soapy water. Also, in the fight against the pest, they use a sprinkle of crushed sulfur and special chemicals that can be used harmlessly at home.
- Aphid Is 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 serious problems arise with the plant. Aphids feed on the cell sap of the leaves, as a result of which they turn yellow and curl, after which they dry out. Fighting aphids on seedlings is quite difficult 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 wrapped in a plastic bag for a day. After the allotted processing time, the seedlings are washed with clean water.
- Whitefly - a frequent visitor to glazed balconies, loggias and greenhouses. This insect looks like a small, light-colored butterfly. As a rule, its fluttering over the petunia ends with the appearance of white age 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 the pest, 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 defeat. Untimely detection or lack of measures to prevent the harmful effects of pests on seedlings leads to the inevitable death of petunias. You can find out in detail about the methods of pest control of seedlings at home in their video:
Diseases
The reason that the foliage of petunias has turned yellow can be a fungal disease - powdery mildew. This disease rarely affects plants growing in protected conditions, however, its source can be untreated soil containing spores of this fungal disease. Often, spores are 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 bloom that covers the leaves of petunias. As a result of this effect, the seedlings lose their elasticity and become lethargic. The leaves under the veil of plaque acquire a yellow and then brown color.
It is possible to rid the seedlings of the disease by treatment with "Fitosporin", "Topaz". Before treatment with these substances, 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 small amount of lemon juice. Regularly (once every 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 nutrition and prosperous existence for them. So, only an attentive, caring owner will receive healthy, strong seedlings of petunias as a reward for his labors, which will decorate flower beds and pots with bright, beautiful flowers.
