Diseases and pests

Spider mites

Spreads to other plants

What it looks like

Tiny pale dots on the leaves, as if pricked with a needle. Fine webbing on the leaf undersides and in the joints. Leaves gradually go grey and dry out. The mites are nearly invisible — use a magnifier or zoom in on a photo.

Why it happened

Dry warm air, typically above a radiator in winter. Mites multiply extremely fast in those conditions.

What to do

1. Isolate the plant immediately — mites spread. 2. Shower the whole plant with lukewarm water, especially the leaf undersides. 3. Spray with water plus a few drops of dish soap, or neem oil, every 3 days for at least 3 weeks. 4. Raise humidity — a tray of water and pebbles beside the plant. 5. Finish the full cycle. One treatment is never enough; the eggs survive.

How to prevent it

Wipe the leaves with a damp cloth weekly in winter. Do not place plants directly above a radiator. Keep new plants separate for the first two weeks.

Most common on these species

  • Calathea
  • English ivy
  • Parlour palm
  • Weeping fig
  • Elephant ear
  • Areca palm
  • Croton
  • Japanese aralia
  • Pygmy date palm
  • Banana plant
  • Passion flower
  • Ming aralia
  • Chilli pepper
  • Swiss cheese plant
  • Dumb cane
  • Swiss cheese vine
  • Prayer plant
  • Stromanthe
  • Pink jasmine
  • Kentia palm
  • African hemp
  • Oleander
  • Chinese hibiscus
  • Jerusalem cherry
  • Creeping fig
  • Dwarf fan palm
  • Ti plant
  • China doll
  • Never never plant
  • Ornamental pepper
  • Fuchsia
  • Lemon verbena
  • Rose
  • English ivy (outdoor)
  • Norway spruce