Powdery MildewPowdery Mildew

 What is Mildew?
Powdery mildew is a fungal disease of the foliage, stems and occasionally flowers and in very severe cases even the fruit are effect by a superficial fungal growth that covers the surface of the plant.  But what can we do about this disease?

What to Look for:

You may see the following symptoms:

Vegetable plants most often affected:

About the Powery Mildew

The fungus likes warm dry conditions, especially because we have to water frequently, which creates local high humidity around the plants. Rainy weather is not the problem, but rather hot, still, dry conditions followed by a blast of high humidity, such as... when we water. 

Control Measures

Since powdery mildew thrives in hot, dry conditions with high local humidity around the plant, the easiest way to control it is really to prevent it in the first place by depriving it of what it needs.

How yo water your plants can have a huge say in whether your plants develope the disease or not, if you use a watering can remove the rose and do your best to water the soil, not the plant leaves, thus cutting down the enviroment that the fungus needs to thrieve.

Give your plants room the breath, plants spaced out have better air circulating around them making less localised humity zones.


Non-chemical control
Chemical control

Because most of the growth of powdery mildews is found on the plant surface they are easily targeted with fungicides.  Potassium Bicarbonate is particularly effective and easily purchased relatively cheaply from eBay etc

Edibles and ornamentals: Myclobutanil (Bayer Garden Systhane Fungus Fighter concentrate*) can be used on ornamentals, apples, pears, gooseberries and blackcurrants.

Potassium bicarbonate Fungicide - Also great as a Blight preventative
Bicarbonate of Soda Fungicide