Downy mildew

Downy mildew is a water mould, a fungus-like microorganism.

Do not confuse with:
Powdery mildew

recognize downy mildew
Downy mildew on sunflower photo: Rob Hille - CC BY-SA 3.0

Downy mildew (Peronosporaceae species) is a water mould (Oomycetes), a fungal microorganism.
With downy mildew, the lint is on the underside of the leaf instead of the on the top (powdery mildew). The spores hibernate on the ground and in the spring these end up on plants via splashing water.
Several plants have their own specific water mould, for example: grapePlasmopara viticola, spinach –  Peronospora effusa, cucumberPseudoperonospora cubensis, kale and cauliflowerPeronospora parasitica, rose – Pseudoperonospora sparsa.

Where to find

  • Vegetable plot and ornamental garden


Remove yellowed leaves. Dispose of the affected leaves in the kerbside garden / food waste; do not put them in the compost pile.


Providing enough space around the plants, so that the wind has free play between the crops.
Clean up fallen leaves in the fall.
Ensure a dry climate in the greenhouse (airing, heating) so that leaves do not become damp.