How to Care for Orchids: Complete UK Guide

Moth orchids, Phalaenopsis, are among the most popular flowering houseplants in the UK, prized for their long-lasting blooms and elegant arching spikes. Grown in a specialist bark mix rather than compost, and given bright indirect light with weekly watering and good drainage, they can reflower reliably for many years with the right ongoing care.

Choosing a healthy plant and varieties

Look for firm, unwrinkled leaves, several visible silvery-green roots, and buds still to open on the flower spike so you get maximum flowering time at home. Avoid plants with yellowing leaves, black spots, or roots that appear mushy and brown through the clear pot.

Light and position

Orchids need bright, indirect light, such as an east-facing windowsill, to flower well; direct sun can scorch leaves while too little light prevents flowering altogether. In UK winters, a south-facing windowsill with sheer curtain protection or a spot a little further back from the glass works well to balance light and warmth.

Watering

The bark mix should almost dry out between waterings. Soak the pot in room-temperature water for 10-15 minutes once a week in summer, or every 10-14 days in winter, then allow it to drain thoroughly before returning it to its decorative cover pot. Never leave orchids standing in water, as this is the leading cause of root rot.

Humidity and temperature

Orchids appreciate humidity of 50-70%, which can be achieved with a pebble tray, regular misting of aerial roots, or a bathroom windowsill with good light. Maintain a stable temperature of 18-24°C, avoiding cold draughts and sudden temperature swings, both of which can cause buds to drop before opening.

Feeding

Feed every second or third watering during spring and summer with a specialist orchid feed diluted according to the packet, switching to a high-potassium bloom booster formula as flower spikes develop. Reduce feeding in autumn and winter to roughly once a month, matching the plant's slower growth.

Potting mix and repotting

Orchids need excellent airflow around their roots, which ordinary compost cannot provide.

1. Choose a clear plastic pot with drainage holes to monitor root health.
2. Use a specialist orchid bark mix, ideally with added sphagnum moss or perlite.
3. Remove the plant and gently rinse old, degraded bark from the roots.
4. Trim away any brown, mushy roots with clean scissors.
5. Repot into fresh bark, positioning roots evenly, and water lightly after a few days.

Pruning, cleaning and support

Once a flower spike has completely faded and turned brown, cut it off near the base; if it is still green, cut just above a node to encourage a secondary spike. Wipe leaves gently with a damp cloth to remove dust, and use a slim stake and soft ties to support heavy flower spikes as they grow and arch.

Propagation

Phalaenopsis are usually propagated via keiki, small plantlets that occasionally form on the flower spike.

1. Wait until a keiki has developed its own small roots, at least a few centimetres long.
2. Using clean, sharp scissors, cut the spike a few centimetres either side of the keiki.
3. Pot the keiki into a small container of fine orchid bark.
4. Keep in warm, humid, bright indirect light while it establishes.
5. Water lightly and treat as a young orchid once new growth appears.

Common problems

Seasonal care calendar

Discover more flowering houseplants in our plants section, or browse our full plant directory for further growing advice.