Content
- White coating on the petunias: what is it?
- Location and care for less susceptible petunias
- The downy mildew
- The powdery mildew
- Tips
White coating on petunias is almost always mildew
White coating on the petunias: what is it?
Not only petunia, but many other plants in the garden can sometimes have a rapidly spreading, white surface. As this is a fungal disease that is immensely harmful to plant health, appropriate preventive and control measures should be taken as part of petunia care.
Location and care for less susceptible petunias
Petunia originates from natural habitats in South America and thrives particularly well in warm, sunny locations. However, uncovered locations in the garden can make the popular balcony plant due to the often regular rainfall here in front of problems. If lush, hanging petunias stand very close to each other, they can only dry poorly after rainfall, which favors some fungal diseases. In addition, the real as well as the downy mildew can spread particularly easily in the garden or on the entire balcony when the plants are very close together, since then the fungal spores have to cross only short distances.
The downy mildew
The downy mildew is distinguished from powdery mildew by the fact that the white deposit on the plants is mainly observed on the underside of the leaves. At the same time yellow and brown spots appear on the upper sides of the leaves until the leaves finally wither away. Mildew is especially susceptible to excess moisture, which can become a problem in rainy summers and in less sheltered areas of the petunia. In the case of any kind of mildew, small infestations should be cut out and removed as early as possible so that the further spread can be stopped or at least contained. For this a regular check is necessary, also with a hibernation in the house.
The powdery mildew
In powdery mildew, the fungus visible as a white plaque spreads mainly on the tops of petunia leaves, but also affects all other parts of the plant. The powdery mildew is favored by the alternation of wet periods and dry phases. Therefore, it can be prevented by cultivating the petunia under roof and pouring it sufficiently in dry seasons. For the treatment of both mildews the following applies:
In addition, spraying the affected areas with a mixture of 9 parts of water and one part of commercial milk helps.
Tips
The white powdery mildew is a problem not only for the petunias, the dangerous fungus can also skip on other plants in the garden such as cucumbers, salsify and dahlia.