Scale Insects on English Ivy: Brown Bumps on Stems
English Ivy (Hedera helix)
Symptoms
- Flat or dome-shaped brown bumps on stems, especially in node areas
- Bumps resist wiping — require scraping to remove
- Sticky honeydew on leaves below infested sections
- Sooty mold developing on honeydew-coated surfaces
- Slow, unexplained general decline
Causes
Soft scale and armored scale species establishing on ivy stems
Indoor English ivy is most often colonized by brown soft scale, a species that tolerates a far wider temperature range than spider mites do. Unlike spider mites, scale insects don't die back in the cool rooms English ivy prefers, so keeping the plant at the lower end of its comfort range does nothing to discourage them — particularly if it arrived from a nursery batch that was already carrying scale. Because the woody stems already have a rough, mottled texture, a light scale infestation there can go unnoticed for weeks.
How to Fix It
- 1
Inspect stems carefully with a hand lens. Run a fingernail along stems — scale bumps have a distinct hard, raised feel different from normal stem texture.
- 2
Work down each stem's node sections with an alcohol-dipped cotton swab, since that's where scale clusters densest on ivy — a full-strength (70% isopropyl) dab kills the insect and loosens its shell so it wipes away.
- 3
Follow with a horticultural oil spray to all stem surfaces. Repeat the oil treatment 14 days later.
- 4
For severe infestations: apply a systemic insecticide drench (imidacloprid granules in soil). Effective for 4–6 weeks. Do not use on plants that may be flowering.
Prevention
- Inspect stems monthly — scale on ivy is not self-limiting in the way spider mites are in cool conditions
- Quarantine new ivy before placing near existing plants
- Wipe stems with a damp cloth monthly
Quick Summary
| Plant | English Ivy (Hedera helix) |
|---|---|
| Category | Pests |
| Likely causes | Soft scale and armored scale species establishing on ivy stems |
| Fix steps | 4 steps — see above |