How to care for a Phalaenopsis orchid (moth orchid)
Phalaenopsis spp.
A moth orchid is not a fussy plant once you stop treating it like one. It wants bright indirect light and a weekly soaking of its bark — then full drainage, because roots left standing in water rot fast and that, not neglect, is what kills it. A 5–8 °C night-to-day dip coaxes out the next flower spike.
Care at a glance
- Light
- Bright indirect light, no direct midday sunAn east-facing windowsill is ideal; behind a sheer curtain on a south window also works. Leaves should be a fresh grass-green, not dark (too little light) or yellow-red (too much).
- Water
- Soak the bark weekly, then drain completelyTake it to the sink, run tepid water through the bark for a minute, let every drop drain, and never leave water in the decorative outer pot. Silvery roots mean thirsty; green roots mean satisfied.
- Soil
- Coarse orchid bark, never standard compostThe thick roots need air around them. Repot into fresh medium-grade bark every 2–3 years as it breaks down.
- Humidity
- Moderate; 50–70% suits it bestA pebble tray or grouping with other plants helps in a dry, heated room.
- Temperature
- 18–25 °C (64–77 °F) by dayA 5–8 °C cooler night in autumn is what triggers a new flower spike.
- Difficulty
- EasyForgiving if you master the soak-and-drain rhythm and resist overwatering.
- Pets
- Non-toxic to petsNon-toxic to cats and dogs (ASPCA). A curious nibble may still cause mild stomach upset, as any plant material can.
Where it comes from
Propagation
Moth orchids are difficult to propagate at home and are not divided like many houseplants. Occasionally a plantlet called a keiki forms on an old flower spike, growing its own leaves and roots. Once that keiki has two or three roots a few centimetres long, cut the spike either side of it and pot the baby into its own small container of bark.
Common problems
- Wrinkled, leathery leaves
Likely cause: Usually a root problem — either rot from staying wet, or dehydration from a long-dead root system that can no longer drink.
Fix: Slide the plant out and inspect the roots: firm and green or silver is healthy, brown and mushy is rotted. Trim the dead roots and repot into fresh bark.
- No new flowers for a long time
Likely cause: It rarely re-spikes without a cool autumn night-time drop to cue it.
Fix: Give it a 5–8 °C cooler spot at night for a few weeks in autumn while keeping the light bright.
- Buds shrivel and drop before opening
Likely cause: Bud blast — a sudden change in temperature, draught, or light.
Fix: Keep it away from radiators, cold windowsills, and front doors while it is in bud, and avoid moving it.
Frequently asked questions
Should I cut the flower spike after my orchid finishes blooming?
If the spike stays green, cut it just above a lower node and it may branch and rebloom from there; if it turns brown and woody, cut it back to the base instead.
Why are my moth orchid's aerial roots climbing out of the pot?
That is completely normal — these are epiphytes that anchor to tree bark in the wild, so they send roots into the air. Leave them be and mist them occasionally.
Should I water my orchid with ice cubes?
Better not. These are tropical plants and cold shock can damage the roots; a weekly soak with tepid water gives far more reliable results.
Is a Phalaenopsis orchid safe to keep around cats?
Yes — the ASPCA lists the moth orchid as non-toxic to cats and dogs. As with any plant, a large nibble could still give a pet a mildly upset stomach.
Sources
- RHS — Growing Phalaenopsis orchids — Royal Horticultural Society, checked 2026-06-13
- ASPCA Toxic and Non-Toxic Plants — Phalaenopsis Orchid — ASPCA, checked 2026-06-13