When it sprouted and for the first few weeks afterwards, the dahlia looked very he althy and its leaves radiated with vitality. Now the tide has changed and white spots are appearing here and there that indicate mildew. Reason for concern?
How can you control and prevent powdery mildew on dahlias?
Dahlias are susceptible to powdery mildew, especially powdery mildew, which appears as a white coating on the leaves. To combat mildew, affected parts should be removed and sprayed with home remedies such as a water-milk mixture. You can prevent this through proper planting density and care.
Are dahlias susceptible to powdery mildew?
Unfortunately, dahlias are extremelysusceptible to mildew. It often happens that they are mainly affected by powdery mildew. It is fungal spores that penetrate the top layer of the dahlia leaves and cause the disease.
Why does powdery mildew appear on dahlias?
Powdery mildew, which is also known as 'fair weather fungus', likes to appear onweakened, over-fertilized dahlias. The defense mechanisms are on the back burner and the fungal pathogen has an easy time penetrating the leaves.
Basically, the risk of powdery mildew increases due to sharply fluctuating temperatures. If the days are warm and dry, but the nights are cool and humid, this stresses the dahlias and mildew takes hold.
How does powdery mildew appear on dahlias?
The powdery mildew is noticeable through awhite coating on the leaves of the dahlias. Initially only the top of the leaf is affected. Later you will also be able to see the fungal network on the underside of the leaves. In addition, the leaves of the dahlias turn brown from the edge and eventually curl up.
How can powdery mildew on dahlias be controlled?
Heavily infected parts of the dahlia should best becut off and disposed of. But not in the compost, but rather in household waste. Otherwise, the fungal spores could survive and spread to other plants.
Another strategy is to control mildew withsprays. Make a simple spray, for example from water, oil and baking powder or from milk and water. The mixture is sprayed onto the plant. Alternatively, you can brush the affected parts of the plant with it.
How do you strengthen dahlias so that mildew doesn't stand a chance?
You can strengthen the dahlias with abroth made from plants. Field horsetail, nettles and garlic are suitable for this. The dahlias should be sprayed daily with this.
Another possibility of strengthening is correct care and especially regularfertilization. But not too much of a good thing!
How can you prevent powdery mildew on dahlias?
Plant your dahliasnottooclose together so that air can circulate freely and water on the leaves and flowers can dry quickly. In addition, it is important to water the dahlias from below and not to wet the leaves with water.
Regularly removing weeds between dahlias, properly overwintering the tubers and removing wilted flowers are also crucial points to prevent powdery mildew.
How does downy mildew appear on dahlias?
Downy mildew occurs much less frequently and appears on the undersides of the leaves of dahlias in the form of agray coating, also called fungal lawn. Sometimes light spots appear on the top of the leaves.
Tip
Are there powdery mildew resistant dahlias?
In fact, there are dahlia varieties that have little or no susceptibility to powdery mildew. So if you have had bad experiences with this disease, try the varieties 'Mystic Dreamer', 'Mystic Wonder' or 'Dalaya Amba'.