Moth orchids (phalaenopsis) are deservedly popular as flowering houseplants and have the potential to flower for months, and to live for years. They are tough and resilient and even without the care they deserve they will look good for months. Each flower will last for months and with unopened buds developing, the display should last for six months and more.
When all the flowers have dropped, do not cut off the old flower stem because they should either produce side branches or the tips will extend to produce more flowers. Only when the stem shrivels should it be removed.
General care is to keep the plant in good light but out of direct sunlight. If the spot is too bright the leaves will become scorched, with yellow or brown patches, and if the site is too dark the new leaves will become very elongated and no new flowers will be produced. In theory, for each new leaf or pair of leaves that are produced, a new flower stem will appear. But this only happens if the plant is healthy and it is fed. You can allow the plant to dry out between waterings but never let the plant sit in water for more than a few hours. Water the plant thoroughly and then pour away any excess in the pot cover after a few minutes. If you want to mist it, then go ahead. Feed once every fortnight, with an orchid feed or any other liquid fertiliser you prefer. Any feed is better than no feed but it is best to apply it at half strength. Every few months, flush out the compost with water to remove excess salts. It is fine to plunge the pot in a container of water for a few minutes as long as it is allowed to drain afterwards. The worst thing you can do is add some water every few days so that the compost is always wet.
Phalaenopsis enjoy the same sort of temperatures as us and if your house is kept above 15c then your orchid will be fine. Pests are not that common but scale insect and mealy bugs are an issue and need to be controlled, either by picking them off or using a spray.
After a year or so it may be necessary to repot the plant. Never be in too much of a hurry to do so. These orchids don’t have extensive root systems. But as they age, and lower leaves die, and old roots decay, the plants often get top heavy. When you repot it is usually possible to put them back into the same pot but slightly deeper. What you must never do is use ordinary multipurpose compost. The roots need to breathe and they will suffocate if surrounded by wet compost. I have lost count of the number of homes I have visited that have huge (20cm) pots filled with multipurpose compost with a miserable orchid sulking in the middle. It is just cruelty to plants. Always buy a pack of orchid compost. These are coarse and usually contain bark, which keeps the compost open. But even this deteriorates as it decomposes and the roots in the bottom of the pot can become smothered in fine particles.
So repotting is necessary after a year to two years.
Start by cutting off old flower stems, removing dead leaves (you can usually pull them off sideways) and check for pests. Then take it out of the pot.
I have also been repotting my sarracenias. I got these last year – ex pot – and I hoped that orchid compost would work because I didn’t have any sphagnum moss to hand. The compost must be free of nutrients and moss, with peat and sand comprising the usual potting mix. But the bark-based orchid mix seemed to work so I have used it again. The only problem is that it does not take up water, by capillary action is poor so I have to keep the tray, which holds rainwater, topped up. Acid compost is necessary and rain water is important.
Spring is the time to repot. Cut off the dead, old traps. Plants can produce flat leaves, without traps, in winter. The old leaves can be left if you like. I took off many of the old traps but left some. Already there are flower buds appearing. These can be left on sarracenias but it is best to remove them from Venus fly traps – they weaken the plants and don’t look amazing anyway. On the other hand sarracenia flowers are very exciting. The plants increase by compact rhizomes and one of my plants was easy to divide so I potted a section separately and I may try it outside in the pond – when it is complete. Sarracenias are more or less hardy – Sarracenia purpurea is naturalised in Ireland. Mine are in a cold greenhouse. They don’t need winter heat but they do need bright light so are better as patio plants than as houseplants.