Bunny ears cactus: brown spots
What are the brown spots on the leaves?
On bunny ears cactus, the likeliest cause is water sitting on the leaves. Discrete round spots rather than marginal browning, often with a darker ring, worst after overhead watering or misting.
- 1Water sitting on the leaves
Ranked here because overhead watering is the usual origin of discrete spots indoors.
How to tell. Discrete round spots rather than marginal browning, often with a darker ring, worst after overhead watering or misting.
What to do. Water the soil, not the plant. Where leaves are hairy or crinkled, water from below entirely.
- 2Cold water on warm leaves
How to tell. Pale rings appearing after watering with cold tap water.
What to do. Use room-temperature water.
- 3Scorch
How to tell. Bleached patches on the leaves facing the window, sharply defined.
What to do. Move it back from the glass. A south or west window against the glass. Full sun, and nothing indoors is too bright.
Why that order, for this plant
The ranking above is not a generic list. It is computed from this species' own record — a watering interval of 18–35 days, a arid origin, a humidity floor of 20%, and a light range from direct to direct. Change those figures and the order changes with them.
That is the whole point of a per-species page. Brown spots on a plant watered every three days and brown spots on one watered every three weeks almost never have the same cause, and a list that ranks them identically is worth nothing to either owner. You can check the reasoning against the care fields on the species entry, which is where these numbers come from.
No percentages appear on this page. We have not run a grower survey, and a confident-sounding figure with no dataset behind it is worse than none. Order and distinguishing tests are what we can honestly give.
Other problems recorded for this species
- Root rot act today
- Slow growth monitor
Also for this species
Full care entry with light, watering and soil. How to propagate it. Toxicity to cats and to dogs.
Sources
- Royal Botanic Gardens Kew, Plants of the World Online — Opuntia microdasys Accepted name and family. Checked 2026-09-12.
- ASPCA Animal Poison Control — Opuntia microdasys Relevant if a damaged plant is being chewed rather than merely ailing.
- This database's own care record for Opuntia microdasys — the watering, humidity and light figures the ranking is derived from.
Compiled and edited by Tony Valcarcel · 2026-09-12
Cause ordering is derived from this species' recorded care requirements, and the
derivation is stated above so you can disagree with it. It is not a diagnosis, and
a plant can have two problems at once. How this is sourced.