Home comforts
Monty Don’s most loved indoor plant is a South African stunner – but it can be a demanding house guest, he says
HOUSEPLANTS are the trendiest thing in gardening at the moment. This is based upon real sociological change rather than horticultural fad. When I was in my 20s and early 30s I had a house, garden, job, car, wife and, towards the end of that period, children. This seemed to be true of almost everyone I knew.
But for my children’s generation things are very different. Housing is impossibly expensive, the cost of living in cities is almost prohibitive and the chances of setting up home and starting a family on a secure basis are much lower. The long and short of it is that gardens and gardening seem much more remote to them.
But there is a human need to associate with plants. This is where houseplants come in. You may not own your apartment or room in a shared house – let alone a garden – but you can always take your houseplants with you.
Most of the new wave of houseplants are tough, evergreen and pretty bombproof, for obvious reasons. But one of my own favourites refuses to be comfortable anywhere in my house and is happiest on the floor of the greenhouse. However it is perfectly capable of growing in our homes, given the right conditions – and I forgive its temperamental behaviour because it is gorgeously in flower right now.
It – or they, since I have about 20 – is streptocarpus, or the Cape primrose, with flower colours ranging from deep purple to pinks and white. I used to think I was immune to the allure of any houseplant but I fell in love with Cape primroses 12 years ago while sheltering from a thunderstorm in the Drakensberg mountains in South Africa. As the rain hammered down onto the leaves above the gully where we crouched, I noticed great drifts of streptocarpus growing in deep shade out of an almost vertical bank.
This was an invaluable lesson about what growing conditions they really like: bright light but lots of shade, warmth, moisture, preferably in the air rather than directly at their roots, and never sitting in damp compost.
It’s hard to make the air in some houses damp enough, while remaining warm, for them to be truly happy, but misting them daily helps. They are quite tough so will take a lot of bad treatment before expiring but the quickest way to kill them is overwatering. They should be kept at a temperature of 10-20°C, although they’ll be fine in a greenhouse as long as it’s above 5°C and they have some shade.
If the leaves are flopping and the compost is moist then it is a sure sign of overwatering. Let your plant dry out completely and it should recover.
Likewise, if the leaves are flopping and the pot is very light then give it a good soak.
In spring, feed fortnightly with a high-potash feed like liquid seaweed or a general tomato feed. Keep lightly shaded – an east or west-facing window is ideal. Cut back spent flowers at the base and new ones will appear. Stop feeding in autumn and only water when the leaves are very floppy. They need more light in winter.
The Crystal series flowers all year round so should have more light and warmth, and a weak feed monthly in winter to keep its energy up. I have ‘Crystal Ice’, which is amazingly bountiful with its flowers.
Plants can be divided in spring by gently pulling them apart and repotting.
They need a limited root run so make sure there is no more than a centimetre between the edges of the pot and the existing roots.