Spider Mites on croton
What's Happening
Spider mite (Tetranychus urticae) infestation on Croton (Codiaeum variegatum) proliferates in low-humidity indoor environments below 50% RH. These arachnid pests feed on leaf sap, causing stippling—tiny yellow/white dots on foliage—and fine silken webbing on undersides. The 7-14 day egg-to-adult lifecycle enables explosive population growth in dry conditions that also stress the plant, reducing its defensive capabilities. Croton's thin leaves and preference for high humidity make it particularly susceptible.
How to Fix It
- 1
Isolate plant immediately to prevent spread to other plants
- 2
Shower treatment: Rinse entire plant with strong water spray focusing on leaf undersides; repeat every 3-5 days for 2-3 weeks to break lifecycle
- 3
Apply neem oil: Mix 1-2 tsp neem oil + 1 tsp dish soap per quart water; spray all surfaces including undersides; apply in evening to prevent leaf burn
- 4
Increase humidity: Boost to 60%+ RH immediately—dry air favors mite reproduction while hampering recovery
- 5
Monitor with loupe: Check for remaining mites/webbing weekly; continue treatment 2 weeks after last sighting
- 6
Prune heavily infested leaves: Remove beyond recovery to reduce pest load and improve air circulation
How to Prevent It
Maintain 60-70% humidity via humidifier or pebble tray—mites cannot thrive above 50% RH. Inspect weekly with 10x loupe, checking leaf undersides. Quarantine new plants for 2 weeks. Shower plants monthly to dislodge early colonizers.