Most supermarket orchids arrive in a pot of packed moss, wedged inside a decorative ceramic, with roots that have never felt a breath of air. They flower beautifully for months, then the leaves start to look tired and the roots turn to mush. Repotting is the answer, and it is far less delicate a job than people imagine. The moth orchid on your windowsill, Phalaenopsis, grows on tree branches in the wild. Give it air around its roots, a pot that fits, and a fresh start, and it will reward you for years.
When to repot — and when to ignore the rules
Orchids like to be repotted after flowering, ideally in spring when fresh root tips and a new leaf are starting to appear. That is when the plant has energy to spare and will settle in quickly.
You do not have to wait if something is clearly wrong. Repot sooner if the bark has broken down into dark crumbs, if the moss smells sour, if the pot has no drainage holes, or if you can see brown, limp roots through the side of the plastic. Losing a flower spike is annoying; losing the whole plant is worse.
A plant in full bloom can be repotted, but expect buds to drop. If it is healthy and flowering happily, note the date and come back to it in a couple of months.
Choosing the right pot
Clear plastic pots with slits or holes are the practical choice, and most garden centres sell them for a pound or two. The clear sides let you check root colour and see how damp the bark still is, and the green roots underneath do a little photosynthesis of their own.
Size matters more than material. Go up by roughly two centimetres in diameter, no more. A pot that is too large holds a soggy core of bark the roots never reach, and that is how rot begins. If the orchid is already snug in a pot that drains well, reuse it after a good scrub.
Decorative outer pots are fine as covers, but treat them as cachepots: lift the inner pot out to water, let it drain, then put it back. Water sitting in the bottom of a sealed ceramic is the single most common way these plants die.
The right bark mix
Orchid bark, not compost. Multi-purpose potting soil is far too fine and holds water against the roots, which is exactly what an epiphytic orchid cannot tolerate.
Look for a chunky bark mix — medium grade suits a standard supermarket plant, finer grade for miniature varieties. Many mixes also include charcoal and perlite, which is fine. Avoid anything that looks mostly like peat or sphagnum moss; it will stay wet for weeks.
Soak the bark in a bowl of water for half an hour, or overnight if you have time, then drain it well. Dry bark repels water at first, and you want the plant sitting in damp, not bone-dry, material. Never reuse old bark from a sick plant.
Getting the orchid out without a fight
Squeeze the sides of the plastic pot to loosen things, then slide a blunt knife around the inside edge. Turn the pot upside down, support the base of the plant with one hand, and wiggle gently. Never pull by the leaves — they detach easily and will not grow back.
Pick the old bark out with your fingers rather than yanking it free. Supermarket plants often have a plug of moss packed around the base of the stem; if it is sodden, tease it away with a skewer or soak it briefly in tepid water to soften it.
What to keep and what to cut
- Firm, plump roots in green or silver-grey: keep them, even if they are long and winding.
- Roots with bright green tips: these are actively growing. Handle them carefully.
- Squishy, brown or black roots: cut back to healthy tissue with clean scissors.
- Thin, papery, hollow roots: dead. Remove them.
- Aerial roots outside the pot: leave them alone. They are normal, not a cry for help.
Wash your scissors with soapy water between plants, and if you have trimmed more than a little, leave the plant somewhere warm and airy for a few hours before potting.
Potting up, step by step
- Put a small handful of drained bark in the bottom of the pot.
- Hold the orchid so the base of the stem sits level with, or just above, the rim of the pot.
- Lower the roots in, spreading them downwards. Let any aerial roots drape over the edge.
- Trickle bark between the roots a little at a time, tapping the pot on the worktop to settle it. Do not press it down hard.
- Fill to just below the crown. The point where leaves meet roots must stay visible above the bark, or the plant will rot.
- If it wobbles, clip a kebab skewer to the pot with a hair clip or orchid clip for a few weeks rather than burying it deeper.
If you cut roots, wait a day before watering so the cuts can seal. Otherwise, water gently from the top to settle the bark, then let it drain completely.
Aftercare for the first month
Light: bright but indirect. An east-facing windowsill or a spot a metre back from a sunny south window works well. Direct midday sun will scorch the leaves within an afternoon.
Watering: soak the inner pot in tepid water for ten to fifteen minutes when the bark is nearly dry and the roots look silver rather than green, then let it drain fully. In winter that might be every ten days; in summer, every four or five. Never leave it standing in water.
Humidity: a kitchen or bathroom with a window suits orchids well. A tray of pebbles with water just below the pot, or grouping a few plants together, raises the humidity without wetting the crown.
Feeding: hold off for three or four weeks after repotting, then use a weak orchid fertiliser at roughly half the recommended strength every second or third watering while the plant is growing.
Leave it be. New roots can take a month to show, and a wrinkled lower leaf or two is normal after the move. Keep water out of the leaf joints and the crown; if the centre of the plant ever turns black or soft, that is rot, and it usually starts with a splash that was never tipped out.
The short version
Repot a supermarket orchid after it flowers, into a clear pot only slightly bigger than the roots, using damp bark rather than compost, with the crown left above the surface. Trim the mushy roots, keep the firm ones, water sparingly at first, and give it bright light without direct sun. Do that every eighteen months or so and a plant that cost the price of a sandwich will flower for years.
If every root has gone, do not despair. Cut the flower spike back, keep the plant warm and humid, and wait — new roots often appear from the base within a few weeks. Even the saddest supermarket orchid is usually worth one more chance.