plantatiousMoth orchid (Phalaenopsis)
- Light
- Bright, indirect light
- Watering
- When the top of the soil is dry
- Temperature
- 16–29°C
Moth orchids are the orchids of the genus Phalaenopsis, part of the orchid family, Orchidaceae, and most of the potted orchids sold in supermarkets and garden centers are hybrids of them. In the wild they grow on trees in warm, humid forests from India, China and Japan through Southeast Asia to New Guinea and Australia, and botanists have since folded several smaller genera into Phalaenopsis, among them Doritis and Kingidium. Indoors you grow a moth orchid for its long-lasting sprays of flat, moth-like flowers above a few broad, fleshy leaves.
How fast do moth orchids grow?
Slowly. A healthy moth orchid adds just a few new leaves a year from the center of the plant, and most of what you notice is its flowering: a new flower spike usually appears in autumn or winter, and the blooms can last for months.
A moth orchid grows upward from a single crown, one leaf at a time, and sends out thick roots that often wander over the edge of the pot. In the wild these aerial roots grip tree bark and catch rain, so leave them be. Most new leaves and roots come in the warm, bright months. A spell of slightly cooler nights in autumn often prompts a mature plant to start a flower spike, which then grows slowly for weeks before the first buds open. Too little light is the most common reason a healthy orchid makes leaves but no flowers.
How to care for a Phalaenopsis orchid
Give your moth orchid bright, indirect light, water it when the top of its potting mix is dry, and keep it between 16°C and 29°C. A bright window out of harsh midday sun suits it best: direct sun through glass can scorch the leaves, while too little light gives you healthy leaves but no flowers. It grows in loose orchid bark rather than ordinary soil, because its roots need air as much as water. When the top of the bark feels dry, water it thoroughly, let every drop drain away and never leave the pot standing in water. It likes fairly humid air, so keep it away from radiators and cold drafts.
| Light | Bright, indirect light |
|---|---|
| Watering | When the top of the soil is dry |
| Temperature | 16–29°C |
| Humidity | 50% – 80% |
| Repot every | 2 years |
| Native to | China, Japan, Korea and Taiwan, Indian subcontinent, Mainland Southeast Asia, Maritime Southeast Asia, New Guinea region, and Australia |
| Growth form | Plant that grows on trees |
Sources
- Phalaenopsis (Moon Orchid, Moon Orchids, Moth Orchid, Moth Orchids, Phalaenopsis Orchid, Phalaenopsis Orchids), NC State Extension
- General Care for Phalaenopsis Orchids, Clemson Cooperative Extension
- How to grow Phalaenopsis (moth orchids), Royal Horticultural Society
- Phalaenopsis Culture Sheet, American Orchid Society
- Govaerts R (ed.). WCVP: World Checklist of Vascular Plants, version 16, Royal Botanic Gardens, Kew, CC BY 3.0
Tips
- Water by soaking the pot of bark, then let it drain completely.
- Keep water out of the crown, where the leaves meet, and dab it dry if some lands there.
- Grow it in a clear pot so you can see the roots: silvery roots are thirsty, green ones have just had water.
- When the last flower drops, cut the spike back to its base, or just above a node lower down to try for a second, smaller spike.
- Feed it lightly with orchid food while it grows new leaves, and less in winter.
- Repot into fresh orchid bark when the old mix breaks down and stays soggy, ideally just after flowering.
Are Phalaenopsis orchids toxic to cats and dogs?
No. The ASPCA lists Phalaenopsis orchids, also called moth orchids, as non-toxic to both cats and dogs, and its listing covers the whole genus, so it includes the hybrids sold in shops. A pet that eats a lot of any plant can still get an upset stomach, so if yours keeps vomiting or seems unwell after chewing it, call your vet or an animal poison line. Many other plants sold as orchids belong to other genera, so check the label before you assume the same applies.
Moth orchid care: common questions
How do I get my orchid to bloom again?
Give it more light than you might think, still out of harsh midday sun, and let it feel slightly cooler nights in autumn. Keep watering and feeding it lightly through summer so it builds strong leaves; a mature plant in good light usually flowers again each year.
Where should I cut my orchid stem after it flowers?
If the spike is still green, you can cut it just above a node, one of the small bumps along the stem, and it may branch and flower again. If it turns brown or yellow, cut it off at the base and let the plant rest and build a new spike.
Should I water my orchid with ice cubes?
You can, but it is not the best way. A few ice cubes wet only part of the bark. Soaking the pot and letting it drain wets every root evenly, which is what the plant needs once the top of the mix is dry.
Why are my orchid’s leaves turning yellow?
An old leaf at the bottom yellowing now and then is normal: the plant lets it go as it grows new ones. If several leaves yellow at once, check the roots. Mushy, brown roots mean the bark has stayed too wet, so repot into fresh bark and water less often. Too much direct sun can also bleach the leaves.