How to Grow Hardy Orchids
When I say hardy orchids, I mean those that are likely to grow outside in milder areas of temperate regions. Some are very frost hardy, others will need winter protection, but these are not the warm blooded tropical characters that need cossetting in a glasshouse throughout the year. So they should be easier to grow for anyone that cherishes their plants and likes the idea of growing a botanical treasure. The good news is that in recent years modern propagation techniques have made many of these orchids more available.
Pleione formosana, a lovely little terrestrial orchid from the foothills of Asian mountains is an orchid often mentioned, but too rarely seen. A few years ago it was widely promoted as an easy hardy orchid and was sold in pots of peat with a picture on the top promising eternal beauty. Then the bulbs were often wild collected and directions on how to make them grow were non-existent, even if they were still alive when you bought them. Today, if you buy from a reputable source, pleiones can give many years of pleasure, if you follow a few rules in their cultivation.
Most species like Pleione formosana and Pleione grandiflora need a distinct dormant period. They like cool conditions and they hate summer heat and winter wet. Therefore few will be successful growing in the open ground. They are best in pots, and perfect for alpine house conditions. Pot up the dormant bulbs in late winter in orchid mix which is nice and open and free draining. The bulbs should be nestling on the growing medium surface. Place in a cool, light position and flowers follow in spring. After the flowers fade the leaves emerge, this is the growing period so water and feed regularly with a general liquid fertiliser. A lightly shaded position outdoors is ideal through the summer. Gradually withhold water in late summer and as leaves die back stop watering, move the plants indoors and keep cool. Some take the bulbs out of the pots, wrap in paper and keep in the salad compartment of the refrigerator. A cold garage should suffice. Start again the following season and all should be well.
The other “easy” hardy orchid that is often available alongside summer flowering bulbs is Bletilla striata, sometimes referred to as Bletia hyacinthana. This is easier, and you may well succeed in a sheltered spot outdoors with this orchid. It grows from a corm-like rhizome with pleated leaves, the flowerbuds emerging from among the leaves in summer. It likes good drainage and dappled sunlight. Alongside a wall, in the shade of a tree or shrub is ideal as long as the soil is not too dry. It grows well in a pot or container brought under the eaves of the house in winter to afford some protection. When you buy this one as a dormant “bulb” I recommend you start it in a pot of lime free growing medium with added loam and grit. Get it well established and then plant it out, if growing in the open ground.
If you are not familiar with these orchids it is worth mentioning that photographs can make the flowers appear larger than they are. Bletilla is a good example: the blooms are exquisite, an amazing colour, but they are carried on delicate sprays above abundant foliage. Don’t get them confused with the flamboyance of their tropical cousins.
Calanthe in a genus of terrestrial and evergreen orchids. The hardier species like reasonably moist, humus-rich soils in shade in sheltered situations. They will stand a few degrees of frost occasionally but I can see them succeeding in town gardens with good ground preparation where they could add an exotic highlight amongst ferns, epimediums and other shade lovers. Alternatively grow in pots in a mixture of fibrous loam (you can make that by composting turf), leaf mould, sand and chopped sphagnum moss. They dislike winter wet. Calanthe discolor flowers in late spring. It is a native of woodlands in Japan; worth a go if you have the right conditions.
Hardy cypripediums are definitely enjoying an uplift in popularity in Europe, mainly due to commercial production and good marketing. However, this does not make them any less desirable. The sight of a clump of Cypripedium reginae in bloom will make the pulse of any plantsman race. This beauty, known as the Showy Lady’s slipper Orchid is native of the north east US and south east Canada where it is rare, due to habitat loss. It grows in open fenlands and swamps in neutral soil conditions. However it will establish in a moist situation in the garden in a cool, lightly shaded spot that does not dry out. Add lots of leaf mould before you plant; perfect for the shaded bog garden. Not an ideal subject for a pot I fear.
Cypripedium calceolus, the lady’s slipper orchid is a European native, widespread across Europe to Asia. It was common in northern parts of the UK, but is now virtually extinct. It likes alkaline soil, rich in organic matter and light shade. Again, not a good one for pots and containers but, if you can create the right growing conditions in the garden, it is a wonderful long-lived herbaceous perennial flowering in late spring and early summer. If you have a woodland garden on alkaline soil, definitely give it a go. Providing you can irrigate sufficiently why not create a raised bed in the light shade of deciduous trees and fill with leaf mould and fibrous loam mixed with some gritty sand. A rotting branch or two and a mulch with composted bracken will help.
If UK readers would like to try any of these wonderful hardy orchids, or other glorious flowerbulbs check out https://www.directbulbs.co.uk/ . Not all varieties are available all the time, but do ask for what you are looking for. As a special offer for MyGardenSchool blog readers, enter the promotion code AMC10 into the promotion code box at time of ordering and get 10% discount.
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