The beautiful orchid blossom symbolizing love and tranquility brings a touch of the exotic to the home garden. Orchid growing is not only for the connoisseur or enthusiast. I see plants in most home gardens. Orchids are the prime attractions in flower shows and a few spikes of orchids make a welcome present when visiting friends.
Orchids belong to the botanical family Orchidaceae , the second largest family of flowering plants comprising well over 20,000 species. Orchids are widespread from the Arctic to Antarctic, though growing more abundantly in the tropics.
The vast majority of orchids in Sri Lanka are epiphytes. Epiphytes grow above the ground attached to trees. Their roots hold onto the bark of trees and absorb moisture from the air. These orchids will grow well in your home garden, anchored to tree trunks.
Ground orchids are called terrestrial orchids. These grow like the common plants with their root system below the soil. They are found in the shade of jungles growing in humus. Ground orchids show active growth and flower throughout the year. They can also be grown in pots with a soft and moist potting medium. These plants must be kept in shady spots of the garden and watered lightly.
Orchids with linear growth
Orchids that will do well in the warmth and moisture in your garden are Arachnis, Vanda and Phalaenopsis. These are huddled under monopodial orchids, for they grow aerially with a single apical bud. Arachnis is the famous ‘scorpion orchid’.
Scorpion orchids, vandas and phalaenopsis do not have storage facilities for water or nutrients. They dislike drying up; hence have to be watered regularly. They can be grown in pots but are best attached to tree trunks or some support to grow up in the air.
Orchids growing laterally
The rare Cattleyas and the popular Dendrobiums are also epiphytic orchids. These have a bulbous base – the so called ‘pseudo-bulb’, hence are known as sympodial orchids. The bulb is a temporary store of water and nutrients.
These plants do not keep on growing vertically, but spread out laterally. After some time the main stem or pseudo bulb stops growing. Growth resumes later with a lateral bud. Cattleya and Dendrobiums do not grow tall, but spread out laterally. These are ideal for potting.
Locally grown orchids prefer humidity and warmth. Plants burst into growth during periods of ideal humidity. During dry weather the newly grown shoots mature and begin to flower. Humidity can be adjusted by watering. All orchids do not do well under the same temperature. Some prefer warmer temperatures and others do well in cooler weather.
Orchids grow well in fresh air and under sunlight filtering through branches. All orchids like direct morning sunlight. Adult plants tolerate more sunlight than younger plants.
Sudden exposure to bright sun can scorch the leaves resulting in growth retardation or loss of a plant. So shifting a plant from shade to sun must be done gradually. Under poor sunlight plants become weak and flowering retards. Well growing orchids in bloom is a telltale sign that your home garden has sunlight, ventilation and moisture.
Pigeon (Dove) orchid
This wild orchid is commonly known as the ‘Paraviya’ or pigeon orchid in Sinhala. Its flower bears scent that penetrates through the garden air! It can be established by attaching a plant to a tree trunk or branch. It prefers shade, mild warmth and moisture.
Once established it needs little extra care. Sad to say, it flowers only a few times a year and the flowers last just one day. As the flower unfurls early in the morning swarms of honeybees flock around for nectar – a scene to watch!
Beautifully shaped flowers and an attractive blend of colours characterise the vanda. These can be propagated with cuttings. Arachnis or the Scorpion orchid is a climber and can be grown in beds.
Vandas can be made to climb up trees or a wire mesh or else, stuck to palm trees to climb to their full height. It is a free flowering orchid with the flower taking the shape of a scorpion. Flowers have an excellent texture and keep well for a long time.
Dendrobiums grow well in countries like ours receiving monsoon weather. There are over a thousand species of denrobiums and many man-made hybrids of dendrobes. All these produce long racemes bearing vividly coloured and long lasting flowers.
Phalaenopsis type dendrobiums are ideal home garden orchid plants. These grow to a height of about two feet. Flowers are large, and take the shape of a moth (moth-like) with colours from reddish-purple, lavender, mauve and white.
Each raceme carries ten to fifteen flowers. These plants do not tolerate too much sunshine and must be grown in shade, receiving about 60% sunlight.
The humidity ideal for their growth is around 70% - 75%. When plants are not growing, fertiliser (20-20-20 N.P.K formula) can be applied once a week in good weather conditions. If these plants are exposed to cold rainy weather, they rot.
Orchids in pots
Potted Dendrobiums need care and attention. When the plant outgrows the pot, it starts to deteriorate, decay and die. When overgrowing is detected, say - once a year (plant creeping to the edge of the pot – outgrowing the pot) uproot the orchid plant and remove all the medium (charcoal).
Cut and remove the dead, decaying and excess root, retaining only a few healthy roots. With a sharp knife cut at the base between shoots retaining about 3 to 4 bulbs for the leader shoot. Re-pot the plant in new potting mixture. You have rejuvenated the plant.