How can you get rid of spider mites on kohlrabi? - briefly
Wash the plants with a strong jet of water to dislodge mites, then treat foliage with insecticidal soap or neem oil every 5–7 days, ensuring coverage of both leaf surfaces. Remove heavily infested leaves and, if feasible, introduce predatory mites (e.g., Phytoseiulus persimilis) for biological control.
How can you get rid of spider mites on kohlrabi? - in detail
Spider mites can quickly damage kohlrabi leaves, reducing yield and marketability. Effective management combines preventive cultural practices, direct physical removal, biological agents, and, when necessary, approved chemical treatments.
First, maintain a dry, well‑ventilated garden. Space plants 12–18 inches apart to improve air flow, and water at the soil level rather than overhead to keep foliage dry. Remove weeds and plant debris that can harbor mites, and rotate crops annually to break the pest cycle.
Physical control includes a strong jet of water aimed at the undersides of leaves. A two‑minute spray every 3–5 days dislodges mites and reduces population pressure. For small infestations, wipe leaves with a soft cloth or use a fine‑toothed brush to scrape the pests from leaf surfaces.
Biological options rely on natural predators. Introduce phytoseiid mites such as Phytoseiulus persimilis or Neoseiulus californicus at a rate of 500–1 000 individuals per square meter. These predators consume spider mites throughout their life cycle, suppressing outbreaks without harming the plant. Maintain a habitat for beneficial insects by planting nectar‑rich flowers (e.g., dill, fennel) nearby.
If cultural, mechanical, and biological measures are insufficient, apply horticultural oil or neem‑based insecticidal soap. Dilute oil to 1–2 % (v/v) and spray until runoff covers both leaf surfaces, repeating every 7–10 days. Neem oil formulations should be used at the label‑recommended concentration, applied in early morning or late afternoon to avoid leaf scorch. Both products disrupt mite respiration and feeding while remaining safe for humans and most beneficial insects when used correctly.
Chemical miticides are a last resort. Select products specifically labeled for spider mite control on edible crops, such as abamectin or spirodiclofen, and follow the pre‑harvest interval indicated on the label. Rotate active ingredients to prevent resistance development, and limit applications to the minimum effective number.
Monitoring is essential throughout the growing season. Inspect the undersides of leaves weekly with a 10× hand lens; an infestation threshold of 5–10 mites per leaf warrants immediate action. Record findings to track population trends and adjust management tactics accordingly.