Effective Pest & Disease Management in Greenhouses 

Maintaining Plant Health

Healthy plants, supported by proper nutrition and environmental management, are less susceptible to pests and diseases. However, even with optimal care, common threats such as aphids, mites, and whiteflies can arise.

Natural & Mechanical Pest Control

• Use mechanical methods like vacuuming, hand removal, and rinsing to manage early infestations.
• Deploy yellow sticky traps to capture whiteflies efficiently.
• For larger outbreaks, consider pepper sprays, neem-based solutions, or insecticidal soap.
• Introduce beneficial insects such as ladybugs, lacewings, and parasitic wasps to reduce pest populations.

Creating a Habitat for Beneficial Insects

To support natural pest control, cultivate a dedicated biological area in a well-lit, warm section of your greenhouse. Flowering herbs like dill, chervil, and ornamental plants such as salvias and geraniums will attract and sustain helpful insects.

Preventing Pest Infestations from Outdoor Plants

While bringing in outdoor plants can be tempting, it also introduces risks. To minimize issues:

• Opt for new seedlings or greenhouse-specific transplants.
• If bringing in outdoor plants, quarantine them for 7-10 days in breathable, translucent sacks.
• Monitor for signs of aphids, mites, and thrips before fully integrating them.
• Eliminate infected plants early to prevent widespread infestation.

Controlling Fungal Diseases

Fungal infections are common in greenhouse environments but can be mitigated through proper care:

• Ensure adequate airflow and proper plant spacing.
• Regulate humidity levels to discourage fungal growth.
• Apply fermented nettle tea or compost tea weekly for disease prevention and nutrition.
• Prioritize sanitation, including the removal of sick plants and regular cleanup.

Cultural Practices for Pest Management

Maintaining proper greenhouse conditions is crucial to minimizing infestations:

• Keep the area surrounding the greenhouse clean and well-maintained.
• Thoroughly clean and disinfect the greenhouse between growing cycles.
• Use sterile soil and tools to reduce contamination risks.
• Address standing water to prevent fungal gnat infestations.
• Consider allowing the greenhouse to freeze in winter to naturally eliminate vulnerable pests.

Monitoring & Early Detection

Regular monitoring helps detect and manage issues before they escalate:

• Conduct weekly inspections to check for emerging pest problems.
• Place yellow sticky cards throughout the greenhouse to track winged pests.
• Replace sticky traps weekly for accurate monitoring.
• Seek guidance from a local extension agent if unfamiliar pests are detected.

Greenhouse Pest Control Video Guide

published 3rd June 2025