How can marigolds be saved from spider mite? - briefly
Apply a strong jet of water to knock mites off the foliage, then treat the plants with insecticidal soap or neem oil as directed; repeat every 5‑7 days until the population disappears. Introduce predatory mites (e.g., Phytoseiulus persimilis) and maintain low humidity to discourage reinfestation.
How can marigolds be saved from spider mite? - in detail
Marigolds attacked by spider mites require immediate intervention to prevent leaf loss and plant death. First, confirm infestation by inspecting undersides of foliage for tiny, moving specks and fine webbing. Once identified, begin with cultural controls: increase air circulation by spacing plants 12‑18 inches apart, water at the soil level to avoid leaf wetness, and remove heavily infested leaves.
Next, apply direct treatments. Choose one of the following options, depending on availability and preference:
- Water spray: Use a strong jet of water to dislodge mites from leaf surfaces. Repeat every 2–3 days for two weeks.
- Insecticidal soap: Mix 2–5 percent soap solution (commercially prepared or mild liquid soap) with water. Apply to all leaf surfaces, ensuring coverage of undersides. Reapply after rain or irrigation.
- Neem oil: Dilute according to label (usually 1–2 percent). Spray early morning or late evening to avoid leaf burn. Repeat weekly for three to four applications.
- Horticultural oil: Apply a thin coat of mineral oil-based product when temperatures are between 50–85 °F (10–29 °C). Avoid excessive oil to prevent phytotoxicity. Reapply after heavy rain.
Biological controls complement chemical measures. Release predatory mites such as Phytoseiulus persimilis or Neoseiulus californicus at a rate of 10–20 predators per square foot. Maintain humidity above 50 % to support predator survival.
Finally, monitor regularly. Inspect plants weekly, record mite counts, and adjust treatment frequency accordingly. If infestations persist despite these measures, consider rotating crops, using resistant marigold varieties, or applying a systemic acaricide approved for ornamental use, following label instructions precisely.