How to fight spider mites in home greenhouses? - briefly
Control spider mites in a home greenhouse by inspecting plants frequently, pruning heavily infested foliage, and treating the remaining vegetation with a miticide such as neem oil, horticultural oil, or a mild insecticidal soap, combined with regular water sprays to break up webs and reduce humidity.
How to fight spider mites in home greenhouses? - in detail
Effective control of spider mites in a personal greenhouse requires a combination of cultural, biological, and chemical measures applied systematically.
First, maintain low humidity and adequate ventilation. Mites thrive in dry, stagnant air; increasing air flow and keeping relative humidity above 60 % reduces reproduction rates. Regularly inspect the undersides of leaves with a magnifying lens; early detection prevents rapid population buildup.
Second, remove infested foliage promptly. Prune heavily damaged leaves and discard them away from the growing area. Clean all surfaces, trays, and tools with a mild bleach solution (1 % sodium hypochlorite) to eliminate residual eggs.
Third, introduce natural predators. Predatory mites such as Phytoseiulus persimilis and Neoseiulus californicus consume spider mites at all life stages. Release rates of 1 – 2 predators per square foot, repeated weekly for three weeks, establish a self‑sustaining population.
Fourth, apply horticultural oils or neem‑based products. Dilute according to manufacturer instructions (typically 2 – 3 ml per liter of water) and spray thoroughly, covering leaf undersides. These substances suffocate mites and disrupt feeding without harming beneficial insects when used according to label rates.
Fifth, consider insecticidal soaps. A 1 % potassium salt of fatty acids solution applied in the early morning or late evening prevents leaf scorch. Reapply every 5‑7 days until mite numbers decline, rotating with oil or neem treatments to avoid resistance.
Sixth, employ physical barriers. Install fine mesh screens on vents and doors to exclude mite entry. Use sticky traps (yellow or blue) placed near plant canopies to monitor population density and capture wandering individuals.
Finally, practice crop rotation and avoid overcrowding. Space plants to allow light penetration and air circulation, reducing favorable microclimates for mites. Rotate plant families each season to break the life cycle of host‑specific pests.
By integrating these steps—environmental management, prompt sanitation, biological agents, targeted sprays, barriers, and cultural practices—home growers can suppress spider mite infestations and protect greenhouse crops effectively.