Although delphinium is a flowering perennial that is very easy to care for, it is also very susceptible to, among other things. for powdery mildew.
What helps against powdery mildew on delphiniums?
In order to successfully protect delphiniums from powdery mildew, biological measures such as regular spraying with field horsetail, sage or yarrow decoction can be used. These decoctions have a preventive effect against mildew and other fungal diseases.
What is powdery mildew?
Powdery mildew is caused by a fungus also known as the “fair weather fungus” because it is favored by heat, drought and strong sunlight. An infestation can be recognized by the white, flour-like coating on the top and bottom of leaves, shoots and flowers. The affected tissue browns and eventually dies.
Prevent and combat powdery mildew
If you don't want to spray with fungicides, biological measures sometimes help. However, since prevention is better than treatment, you can also spray them to prevent mildew. Brews made from field horsetail, sage or yarrow have proven particularly successful.
Spraying with field horsetail
In summer, collect a few handfuls of field horsetail and soak the herb in rainwater for a day. The ratio should be around 1.5 kilograms of field horsetail to 10 liters of water. Then cook the whole thing for an hour, after which the broth is diluted in a ratio of 1:5. The broth not only has a preventive effect against mildew, but also against rust, brown rot (on tomatoes) and other fungal diseases.
Tips & Tricks
Yarrow in particular has been used since ancient times to protect plants from fungal diseases. To do this, boil 500 grams of flowers in 10 liters of rainwater and then let the broth steep for three days.
