Pure gardening joy when the first cucumbers can finally be harvested in summer. But be careful! Often joy suddenly turns into anger when white, flour-like spots or a gray coating appear on cucumber leaves. Powdery mildew – the dreaded cucumber disease – how do you get rid of it quickly and permanently?
How to control and prevent powdery mildew on cucumbers?
To combat cucumber mildew, skimmed milk, nettle manure, Sakhalin knotweed infusion or baking powder-rapeseed oil recipe can be used. As a preventive measure, it is recommended to grow mildew-resistant F1 hybrids such as Burpless Tasty Green, Capra and Othello.
What causes powdery mildew on cucumber leaves?
The pathogen is a fungus. Both powdery mildew and downy mildew usually appear at the end of July and attack cucumber plants outdoors and in the greenhouse.
Powdery mildew threatens cucumber plants in dry summer weather. It can be found on the leaf surfaces as a mealy-white fungal growth. Within a short time, the leaves brown and dry out and the cucumber plants die. Downy mildew spreads in damp weather, rain and, depending on the type of fungus, at temperatures of 10° to 18° degrees. It covers the underside of the cucumber leaves with a purple-gray spore lawn. Within a few days, the cucumber leaves turn yellow and die from the edge.
It doesn't rain in the greenhouse, but if the humidity is too high, downy mildew also spreads. Therefore, ventilate the greenhouse well both during the day and at night.
Effectively prevent cucumber mildew
The safest measure to prevent cucumber mildew: Only grow mildew-resistant F1 hybrids such as:
- Burpless Tasty Green
- Capra
- Othello
- Professional
- Restina
- Darina
- Jazzer
- Aksu
- Bellando
Fighting cucumber mildew - the most effective home remedies
Harvesting cucumbers without mildew can be effective both preventively and to save the cucumber plants with these recipes:
- Skimmed milk
- Stinging nettle manure
- Sakhalin knotweed infusion
- Baking powder
Dilute skimmed milk 1:6 with rainwater. Spray over the leaves and water the cucumber plants once a week.
Dilute nettle manure 1:10. Spray cucumber plants if infested. Otherwise, water it regularly. This strengthens the plants and makes them more resilient. The manure also acts as a green cucumber fertilizer. Sachalin knotweed works as an infusion against cucumber mildew. To do this, pour one liter of hot water over 10 g of dried leaves and let it steep for a few hours. Water and spray cucumber plants with it
This baking powder and rapeseed oil recipe is a tried and tested secret recipe for many recreational gardeners to combat cucumber mildew:
- 50 grams of baking powder
- 50 milliliters of rapeseed oil
- some tropical detergent
- 5 liters of lukewarm water
Dissolve baking soda in 5 liters of lukewarm water and then add rapeseed oil and dishwashing liquid. Spray cucumber plants every 2 weeks for a period of 3 months as a preventive measure in the evening.
Tips & Tricks
Do not grow cucumber plants again in the same location after 4 years at the earliest so that they do not become infected with fungi, whose mycelium and spores overwinter in the soil!