Orchid (Phalaenopsis) care: complete guide

How orchids live in nature

Phalaenopsis are epiphytes: in the wild they don't grow in soil but on tree branches in Southeast Asian tropical forests. Their roots — green when wet, silver when dry — are designed to absorb moisture from the air and cling to bark. This origin explains why their substrate is never soil, but chopped bark: the roots need enormous aeration.

Light

Plenty of bright indirect light. Ideal: in front of an east-facing window (soft morning sun) or 1-2 metres from a south-facing window filtered by a curtain. Avoid direct afternoon sun, which burns the leaves.

Sign of insufficient light: very dark green leaves but no flowers for years. Sign of excessive light: yellowish leaves or brown patches.

Soak watering

The best way to water a Phalaenopsis is by soaking: place the clear pot in a container of room-temperature water for 15-20 minutes, until all the bark is wet and the roots turn green. Then lift, drain well for 10-15 minutes and return the pot to its place. Standing water must never remain in the saucer or decorative pot.

Frequency: every 7-10 days in spring-summer, every 10-14 in autumn-winter. How to tell it's time: check the roots through the clear pot. Green means no water needed. Silver-grey means it's time to soak.

Don't use very cold or very hard water: orchids prefer room-temperature water, ideally rainwater or demineralised.

Substrate and pot

Only medium-grade pine bark, never soil. The pot must be transparent (to monitor the roots and support their limited photosynthesis) and pierced with many holes on sides and bottom for aeration.

Bark substrate degrades in 2-3 years: when it goes dark, crumbly and retains too much moisture, replace it.

Repotting

Repot every 2-3 years, right after flowering ends. Slide the plant out, discard old bark, cut rotten roots (black and mushy) with sterilised scissors — healthy silver or green roots stay. Repot in a clear pot the same size or slightly larger with fresh bark.

Fertilising

From March to September, every 15 days with a very diluted orchid-specific fertiliser. Feed only during soaking: add the fertiliser to the soak water.

Flowering and reblooming

A Phalaenopsis flowers for 2-4 months. When the last flower wilts, you have two options: cut the flower stalk above the second or third node from the base (it may push out a new branch in 2-3 months), or cut it at the base (the plant channels all energy into strengthening itself and producing a new flower stalk next year).

To trigger reblooming: move the plant to a slightly cooler spot (16-18°C nights) for 3-4 weeks in autumn. The day/night temperature drop is often the trigger needed for a new flower stalk.

Common problems

• Soft yellowing leaves: overwatering or root rot. Check the roots.
• Brown-black mushy roots: rot. Repot immediately, cutting away compromised parts.
• Leaves creased and dehydrated: very dry plant or most roots lost. Increase soak frequency.
• No flowers for years: insufficient light. Move to a brighter spot and try the autumn temperature drop.
• Mealybugs in leaf axils: remove with a cotton swab and alcohol, treat with potassium soap.
• Aerial roots leaving the pot: normal! Don't cut them and don't force them into the pot.