Orchids: heavenly houseplants

Orchids: heavenly houseplants

With their complex flower structure, intriguing markings and gorgeous displays of often flamboyant blooms in rich purple, ruby and magenta, dusky pinks, pastel yellows, lime and white, orchids have fascinated us for hundreds of years. These are ancient plants. Genetic sequencing indicates that they may have evolved as long as 76 to 84 million years ago.

Found worldwide, orchids grow on every continent except Antarctica, in habitats from lowland tropical forests to mountainous areas and semi-deserts. The glamorous but tender species that we know as houseplants originate in tropical and subtropical areas of the Americas, Africa, Asia and the Pacific. But there are a surprising number of native species in the UK, around 52 of them in fact (there is debate among botanists as to exactly how many). Growing on undisturbed ground, they’re highly adapted to specific habitats, often having evolved relationships with particular fungi and pollinators. They need exactly the right conditions to germinate and can sometimes hybridise, which can make identification difficult – hence the lack of certainty about the number of species.

Tropical and subtropical orchids are valued not just for their beauty, however. Some have culinary uses too. The vanilla that flavours ice creams, cakes and biscuits was originally made from the seed pod of an orchid – Vanilla planifolia. Thought to have first been used by the Aztecs, it’s native to Mexico and Central and South America. The flower is not spectacular, being rather small and a sort of dull yellow, but the pods, black when dried, and which hang like runner beans from the plant, have made fortunes. A twining evergreen vine that can climb up to 15m, it’s now rare in the wild because of habitat loss and overharvesting.

Many orchids are epiphytes, growing on the branches of trees and shrubs and taking moisture and nutrients from the air around them. Some, though, are lithophytes, found on rocks or very rocky soil. And others are unable to photosynthesise, instead taking their food and energy by linking to fungi in the soil.

So it’s perhaps unsurprising that tropical orchids’ beauty, and in some cases their rarity and peculiarity, has generated some very bad behaviour indeed.

Orchid fever ‘Orchidelerium’ was the term coined to describe the Victorian craze for these exotic and, at the time, novel plants. Collectors were commissioned to explore the world seeking out new species. Competition was fierce and the body count not insignificant; hunters, some of whom showed little regard for the inhabitants of the land over which they were trampling, or indeed for the habitats themselves, often died in conflicts with rivals or local people. Details of trips were frequently kept under wraps, with collectors spreading disinformation about the location of new plants that they had found. The most valuable acquisitions were sold at auction on their return, adding to the fevered atmosphere of high stakes competition.

And orchid fever continues. A thriving illegal international trade exists today with social media frequently used as the marketplace. Many orchids are protected in the wild because of their rarity – some are in danger of extinction. Furthermore, the location of newly-found species is often kept secret to prevent the practice of smugglers removing them before they’ve even been officially documented, and potentially rendering them extinct. This being the case, rare species being grown and studied at Kew are given extra security protection, and Eric Hansen’s book ‘Orchid Fever’ tells of a grower in California who cultivates his plants with a submachine gun to hand, just in case!

Houseplants

While some indoor orchids need warm and humid conditions all year, others grow in subtropical areas so like a cooler period to rest over winter. Orchids are generally planted in bark mixes rather than normal compost to mimic their natural growing medium as closely as possible. Those that naturally cling to the branches of trees are sold in clear pots which allow light to reach their roots, which photosynthesise.

Growing tender orchids Phalaenopsis (moth orchids) and cymbidiums are most popular and widely sold. But you may also find other types at different times of the year.

Phalaenopsis can flower up to three times annually, while cymbidiums bloom from autumn until spring. Having both may seem like an indulgence but should ensure that you have the pleasure of orchid blooms for most of the year!

Phalaenopsis prefer to be kept at a minimum of 15 or16 degrees C, while cymbidiums’ ideal temperature is 10-14 degrees C in winter and less than 30 degrees in summer. If you can, move the latter outdoors in summer to a sheltered spot in light or dappled shade. This will help to trigger flowering. Harden them off first though.Phalaenopsis should be grown in clear containers. Cymbidiums, though, can be grown in opaque pots.

Most tropical and subtropical orchids sold as houseplants like bright, but not direct sunlight and humid conditions which are similar to their natural environment, so they often do well on east or west-facing kitchen or bathroom windowsills. Tropical and sub-tropical plants tend to be sensitive to cold draughts, however, so if the windows aren’t close-fitting or double-glazed, it’s best to move plants to another spot when the weather starts to get cold. Misting the leaves (but not the flowers) regularly will help them to thrive in the dry environment created by centrally heated rooms.

Watering: These orchids don’t like being overwatered and may need less water than you might assume. It’s easy to see when phalaenopsis need watering as their roots become silvery rather than green. When checking cymbidiums, lift the pot to see if it feels light.

Use tepid rainwater or boiled, cooled tapwater if possible. Dunk the pot, then lift it out and allow to drain. Or pour water onto the compost from above and allow to drain through. Don’t let them sit in water. Less is more when it comes to orchid watering. A plant that’s unhappy because it’s too dry can usually be rescued but a plant that’s unhappy because it’s been wet for too long is more likely to be unsalvageable. You’ll notice that orchids need less watering (if at all) once the growing season is over.

Deadheading: cut off the faded flowers of phalaenopsis one by one (they have several blooms on each stem), finally snipping off the stem just above a joint as this may encourage another flowering stem to grow. Faded cymbidium stems should be cut to the base. https://www.gardenersworld.com/how-to/grow-plants/howt-to-grow-phalaenopsis-orchids/ https://www.gardenersworld.com/how-to/grow-plants/cymbidium-orchid-grow-guide/

We may not have all the plants listed in our stores but our staff will be happy to suggest alternatives if possible.

Orchids on show

Kew Gardens’ Orchid Festival is usually held in February, offering an opportunity to bask in warmth and colour in contrast to the often chilly, grey weather outside. And the green-winged orchids at Scotney Castle in Kent are at their peak now. Violet with delicate markings, they’re classified as Near Threatened so the lawn on which they grow is a no-go, now-mow area for the duration. They can be easily admired from the path though.

Indoor orchids care may sound a little demanding but actually they require no more input than the majority of other houseplants. Most flats and houses have somewhere with the right light levels and once you establish a watering routine it’s pretty easy to give them what they need. Indeed, some owners find that, left to their own devices in a humid environment, they will do much better than when fussed over.

You can find more fascinating orchid facts here: https://www.rhs.org.uk/plants/types/houseplants/orchid-facts