A greenhouse knows no bad weather and offers all-round protection. Nevertheless, greenhouse cucumbers can also be attacked by diseases and pests. Which typical diseases are particularly dangerous in the greenhouse and how they can be recognized early, prevented and treated effectively.
What diseases occur in greenhouse cucumbers and how can they be prevented?
Typical diseases of greenhouse cucumbers are cucumber wilt, verticillium wilt, leaf spot, powdery mildew and downy mildew. Preventive measures include constant air circulation, consistent humidity, daily opening and nightly closing of vents, and resistant cucumber varieties such as Fablo or foothill grapes.
Causes of cucumber diseases in the greenhouse
The most common causes of diseases in the greenhouse include errors in care or an incorrect climate. That's why it's better to prevent it now. Greenhouse cucumbers are protected from diseases by maintaining a consistent, warm, humid climate in the greenhouse. In practice this means both during the day and on cooler nights:
- constant air circulation
- constant humidity
- daily opening and nightly closing of the ventilation slots or flaps
- Soil temperature above 10° degrees
Effective measures for greenhouse cucumber diseases
Apart from an optimal greenhouse climate and proper cucumber care, resistant cucumber varieties or refined cucumbers are also the safest protection against typical greenhouse cucumber diseases such as:
- Cucumber wilt
- Verticillium wilt
- Leaf spot disease
- Powdery and downy mildew
Infection in wilt and leaf spot occurs through infected moisture droplets or soil particles that are deposited on leaves and fruit. This can happen due to excessive humidity or when watering and watering. Leaves and fruits turn yellow and wilt. The infected greenhouse cucumbers must be removed. Powdery mildew, downy mildew and gray mold are also typical fungal diseases of cucumber plants. Effective preventive measures:
- airy location without drafts
- ideal soil conditions and germ-free soil
- sufficient planting distance
- no waterlogging
- resistant varieties such as Fablo or foothill grapes
- Sprays with skimmed milk and field horsetail tea
In addition, regular doses of nettle, field and horsetail manure are recommended. Or spraying with field and horsetail tea increases the resistance of cucumber plants. Without chemical measures, infected plants must be removed and the soil completely replaced.
The four most common greenhouse cucumber pests
Greenhouse cucumber plants do not remain pest-free despite all-round protection. Too much moisture, heavily compacted plants, too little ventilation or incorrect care often promote pest infestation. If you discover these pests under glass, immediate action is required:
- Aphids
- whitefly
- Thrips
- Spider mites
Effective countermeasures for small infestations in the greenhouse: Beneficial insects such as ladybirds, lacewings, parasitic wasps and yellowboard help with aphids, whiteflies and thrips. Spider mites are the favorite food of predatory mites.
Tips & Tricks
Whether outdoor cucumbers or greenhouse cucumbers – both swallow a lot of irrigation water. Make sure you find the right balance. Because drought makes you susceptible to powdery mildew and soil that is too moist makes you susceptible to downy mildew.
