Question by Kathryn B.
I have a hydrangea in a large pot on my balcony, and it keeps getting a powdery mildew type fungus. At first, the leaves look coated in a fine white powder, but then they start turning black and shriveling up from the tips/edges of the leaves inwards. I have tried an anti-fungus spray but it doesn't seem to have made any difference. I live on the Mid North Coast, NSW.
Sarah's answer
Hi Kathryn,
That doesn’t sound very good. Powdery mildew, although a fungal disease, is often brought about by environmental conditions and in particular moist, warm humid weather. We can’t change the weather, but there are things we can do to reduce the risk.
Firstly, as your plant is in a pot consider moving it to somewhere with a bit more airflow. When watering your plant, water right down at the soil and avoid wetting the leaves. The morning is the best time to water to avoid creating humid conditions.
Remove the worst affected leaves and clean up any fallen leaves from the soil to prevent the spread of the spores. It can be a good idea to thin out some of the foliage to prevent an overcrowding situation, which can encourage fungal diseases.
Make sure your plant is well fed so it is healthy enough to fight off disease. Plants in pots rely on you for all their food as it can’t go out to find it on its own, so this is important to keep it well fed. A seaweed tonic can help plants to recover from stressful situations. And of course, spray at the first sign of a problem to avoid it becoming unmanageable.
I hope this helps and your hydrangea recovers.
Cheers Sarah : o)
