How can you combat spider mites in a greenhouse using folk remedies? - briefly
Use a neem‑oil spray, a garlic‑pepper infusion, or diluted insecticidal soap applied weekly to foliage, and dust plants with diatomaceous earth to desiccate and deter spider mites. Combine these treatments with regular leaf cleaning to break the pest cycle.
How can you combat spider mites in a greenhouse using folk remedies? - in detail
Spider mites thrive in warm, dry greenhouse conditions, so the first step is to lower humidity and increase air circulation. Adjust ventilation fans to maintain relative humidity above 60 % and keep temperatures under 80 °F (27 °C). Regularly inspect the undersides of leaves with a magnifying glass; early detection prevents rapid population growth.
Cultural and mechanical tactics
- Remove heavily infested foliage and discard it away from the structure.
- Introduce fine mesh screens on vents to keep mites from entering.
- Place sticky yellow traps near plant canopies to capture wandering adults.
- Rotate crops annually; avoid planting the same species in the same bench for more than two seasons.
Traditional botanical sprays
- Neem oil – Mix 1 % (10 ml per litre) cold‑pressed neem oil with a few drops of mild liquid soap as an emulsifier. Apply to both leaf surfaces every 5–7 days until populations decline.
- Garlic‑pepper decoction – Crush 5 g garlic cloves and 1 g hot pepper, simmer in 1 L water for 15 minutes, cool, strain, and add 1 % (10 ml) liquid soap. Spray until runoff; repeat weekly.
- Soap‑based insecticide – Dissolve 2 % (20 g) pure castile soap in 1 L water, add 0.5 % (5 ml) vegetable oil to improve leaf coverage. Apply in the early morning or late afternoon to avoid leaf scorch.
- Citrus oil spray – Combine 5 ml orange or lemon essential oil with 1 L water and 1 % (10 ml) dish‑soap. Use a fine mist sprayer; reapply after rain or heavy watering.
Fermented plant extracts
- Compost tea – Steep mature compost in water (1 kg per 10 L) for 24 hours, aerate constantly, then filter. Dilute 1 : 5 with fresh water and spray. The microbial load competes with mites and disrupts their feeding.
- Basil‑mint infusion – Blend equal parts fresh basil and mint, steep in hot water for 10 minutes, strain, add 1 % soap, and spray. The strong aromatic compounds repel mites.
Physical barriers
- Wrap the stems of vulnerable plants with copper tape; copper interferes with mite respiration.
- Place reflective aluminium foil strips on the greenhouse floor to disorient moving mites.
Monitoring and record‑keeping
- Keep a log of inspection dates, infestation levels, and treatments applied.
- Adjust treatment frequency based on mite counts; cease applications once populations fall below economic threshold (typically <5 % leaf damage).
By integrating humidity control, mechanical removal, and a regimen of homemade botanical sprays, growers can manage spider mite outbreaks without resorting to synthetic chemicals. Consistent observation and prompt action are essential to maintain a healthy greenhouse ecosystem.