The reasons for the color change of petunia leaves: why do they turn white, lighten and become pale green?

Due to the beauty of flowers and undemanding care, petunia is a great success with housewives and gardeners. This pleasant and tender plant is placed on balconies and window sills; in the summer, it adorns flowerbeds and terraces.

In rare cases, even with good care, a white coating may appear on the leaves. Why do the leaves turn white and what should I do if white spots appear? Consider the possible causes and ways to fix this in this article. Also watch a helpful video on the topic.

Features of flower growth

Petunia grows in the form of small low bushes. Their height varies from species: from 15 to 30 cm. Tall varieties of petunias are also bred, but they are less common in our regions. The leaves of the plant are dark green, the shape is oval. The color of the inflorescences is diverse. The size of the flowers is from 5 cm to 13 cm in diameter, they are expressive and delicate.

ATTENTION: Foreign breeders divide the petunia into 2 species, depending on the form of growth. The first is trailing plants. This is a creeping shape when the width is greater than the height. The second type is the ampel. Use such grades for hanging containers.

Diagnose a problem

In 90% of cases, the appearance of white spots or plaque on the leaves is explained by the progression of powdery mildew on the petunia, a dangerous fungal disease. White plaque on petunia leaves resembles white dust. In the initial stages, only the lower leaves whiten, then all parts of the plant become infected. Later, the foliage turns yellow, fades, curls.

What are white spots on flowers? Fungi invade cells and begin to absorb nutrient juice from petunias. Leaves atrophy, dead spots turn white. If the infected area grows, the photosynthesis process is disrupted (emergency measures are required).

Whitish spots are a symptom of a disease such as downy mildew. You can distinguish this disease from powdery mildew by analyzing the spots on the leaves. With a false shape, the spots on top have a pronounced fluffy light coating. Diseases also vary according to the development conditions: the real one appears due to high humidity, false - due to lack of water.

In chlorosis, white spots are caused by an excess of calcium. The element negatively affects the general condition of the plant. White spots on the leaves are areas where the maximum number of trace elements is contained.

You can read more about white, as well as gray and sticky plaque on petunias here.

Causes of disease

With proper and regular care, powdery mildew does not attack the plant and does not provoke the development of white spots. Among the main reasons for the appearance of such a problem, flower growers distinguish:

• the soil contains a lot of nitrogen;
• the pot is small for petunia;
• improper mode of moistening, frequent watering or drying of the soil (white spots - the result of impaired immunity and the onset of disease);
• watering infected with fungi water.

Why does the plant brighten and turn pale green?

This condition is caused by a complex of factors: low temperature and high humidity. Complicating the problem is the untimely removal of affected or fallen parts of the petunia. The plant becomes infected through the smallest damage to the leaf plate. Pale green spots are also a result of malnutrition. If the petunia lacks useful elements and fertilizing, its leaves lose their color, become covered with pale spots.

How to cure?

All affected leaves must be cut, healthy parts treated with special preparations. For these purposes, Previkur, Topaz, Fundazole, Fitosporin are suitable. The dosage depends on the number of affected leaves and the general condition of the plant. A strong or weak solution may be needed. See the exact dose in the instructions.

Among folk recipes that have proven their effectiveness, the following can be distinguished:

1. In 4 l of warm water, dissolve 1 tbsp. soda, 0.5 tsp any liquid soap. Mix thoroughly. To completely dissolve the components, you can hold the solution in a steam bath. Spray 3 times, the interval between repetitions is 6 days.
2. Dissolve 3 g of potassium permanganate in 10 l of water. Stir, pour into a spray bottle. Spray the affected leaves 3 times a day for 4 days.
3. In 10 l of boiling water dissolve 2 tbsp. mustard. Wait for cooling. Spray the affected part of the petunia with the resulting product.
4. Pour 1 kg of crushed ash into 10 l of water. Put the mixture in a dark place for 5-6 days. Stir periodically. After insisting, a working solution is obtained. Spray them every day. The minimum number of treatments is 3 times.

Preventative measures

TIP: To prevent the appearance of white spots, simple actions will help. The main rules of prevention are the optimal soil composition (not heavy, not acidic), timely watering, moderate application of nitrogen and calcium to the soil.

It is important that the water does not stagnate in the pot. For these purposes, you need to make good drainage at the bottom. Petunias should be watered 1 time per day in the late afternoon.

Useful video

Watch a video about the causes of petunia disease and how to solve these problems:

Conclusion

White spots on the leaves of petunias are a sign of powdery mildew, downy mildew or chlorosis. Such a problem appears due to temperature differences, high soil moisture and infection with fungi, an excess of calcium. You can deal with the problem with the help of chemicals or folk remedies.