Aphids or mealybugs
Soft bugs clustered on the tender stems and fresh growth are aphids or mealybugs.
Diagnosis
Aphids or mealybugs
What's happening
Aphids are small, soft, pear-shaped insects — often green — that gather on the newest stems and flower buds, while mealybugs look like little tufts of white cotton tucked into leaf joints. Both pierce the soft tissue and suck sap, which weakens the plant, distorts new growth, and leaves a sticky residue that can turn black with sooty mold.
How to fix it
Wipe away visible clusters with a cotton swab and dab mealybugs directly with one dipped in rubbing alcohol. Then spray the whole plant thoroughly with insecticidal soap, coating stems, leaf undersides, and the crevices where leaves meet stems, and repeat every five to seven days until no new bugs appear. Keep the plant isolated from your others until it's fully clear.
What fixes it
- Insecticidal soap — Insecticidal soap dissolves the protective coating on aphids and mealybugs on contact, with no harsh residue on the delicate leaves.
If that doesn't fix it
This is general guidance based on common symptoms; individual plants vary.
Read the full Purple Shamrock care guide →
Reviewed June 2026 · how we check this