One of the most popular talks I gave to gardening clubs in 2017 was ‘Happy, Healthy Houseplants – The Indoor Jungle’, where I try to help gardeners across the land get the best from their houseplants. According to the horticultural industry, houseplants are now very much on trend and sales were up last year. All good news – least of all that it might mean I’ll be giving more of this talk this year!
And it looks like we need all the help we can get. Gardeners in the UK are renowned across the world for two things when it comes to houseplants: buying the least – and killing the most. I think the two are linked, since in many countries houseplants are throwaway items. They’re bought to look great as ornaments, and then chucked out when they start to go over. But, oh no, not in the UK. We’ll never throw out a houseplant – even if it’s just a small stump tentatively hanging on to its last manky leaf, we’ll still give it a final fighting chance.
The one plant that has become incredibly popular in recent years – now our best selling flowering houseplant – the one plant that I always get asked to talk about, and the one that seems to cause more angst than any other is the moth orchid, Phalaenopsis.
When I managed garden centres back in the 1980s we sold orchids – not many of them, probably because they were so expensive, costing anything around £16-£20 in those days – and they were seen as difficult and exotic. But now thanks to micropropagation, they are far cheaper and also regarded as easy and commonplace. How things change.
There’s probably a good chance you bought or received a moth orchid for Christmas, so how do you ensure you get the best from it? Here’s some hints and tips on not allowing your Phalaenopsis becoming a victim.
And you can check out our video on orchid care.
Location, location, location
As with all houseplants, proper placement is vital. Orchids prefer bright, but filtered, indirect sunlight or light shade – they hate strong, direct sunshine. In their natural environment, they grow on trees, where the tree’s leaves filter the sunlight. They also dislike draughts and widely fluctuating temperatures. Phalaenopsis need a minimum temperature, including at night, of 16-18C (60-64F) rising to 18-29C (64-85F) during the day.
Then it’s just a simple matter of looking after them properly.
Orchids hate wet compost, which causes their roots to rot. So make sue you don’t overwater them – the main reason for killing all houseplants. Depending on the temperature, you may need to water around once a week – or even less frequently. Always use tepid water, as cold water will shock the plants.
Either water from above to thoroughly dampen the compost, or plunge the pot in a sink of tepid water, but allow excess water to drain away immediately.
If your orchid produces lots of very long roots, this is probably a sign that it isn’t getting enough water or the atmosphere isn’t humid enough. Healthy orchid roots that are getting enough moisture are firm and green, but they turn silvery-grey when dry.
Thinking about their natural habitats – rainforests and very humid environments – orchids need high air humidity – higher than naturally occurs in most homes. So, daily misting of the foliage and aerial roots with a hand mister is essential – even more important than watering.
Or you can stand the pot on a saucer or tray filled with hydroleca or gravel that is kept moist.
Most orchids are not very heavy feeders, but need a regular supply of nutrients to keep them looking great and flowering well. But as Phalaenopsis have a long flowering period, they’re much hungrier than most other orchids. Feed them three out of every four waterings; use plain water for the fourth. Flower Power at half its normal recommended dilution is perfect for orchids.
As orchids can absorb nutrients through their leaves and benefit from foliar feeding, add the fertiliser to the water in the hand mister.
We don’t regularly repot most of our houseplants – well, we shouldn’t; you should only repot when they actually need it. But orchids need regular repotting. This always gets a laugh at my talks – because by regular I mean every three to four years.
Moth orchids are epiphytic – in their natural habitat they grow on trees – which is why we grow them in specialist bark-based orchid compost. This provides the open, free-draining conditions that orchids need. If used for too long, the compost breaks down, which reduces drainage and prevents air reaching the roots and causes root rot.
When repotting, carefully remove all the old compost and cut away all brown and soft dead or dying roots.
If the roots haven’t grown much, you can re-use the old pot after cleaning it. If the plant has become potbound then use a bigger pot – but only one or two sizes bigger than the original one. Orchids often form aerial roots outside of the pot.
Spring is the best time to carry out any re-potting – after flowering for those that flower at this time of year.
Dealing with the flower spikes after flowering is also important, have a look at our video on orchids for more on this.