Cultivating Orchids

Cultivating orchids can be a most rewarding and fascinating pursuit, partly because there are so many varieties to experience and partly because of the remarkable nature and adaptability of these plants. They are the single largest and most varied group of all flowering plants. Orchidaceae, as the family is known, has some 30,000 varieties of known orchids, with more than 70,000 registered hybrids —and this number is increasing every year.

Types

Most orchids are epiphytes, which means they grow on trees, not as parasites, but as lodgers, using the host tree as a base from which they can easily absorb carbon dioxide from the air, and nourishment from the rain and any rotting debris. Epiphytic orchids are noted for their swollen stems, which are known as pseudobulbs. These store reserves of food and water. Some orchids have aerial roots that take in nutrients and moisture from the air around them. As well as these air dwellers, there are also terrestrial orchids which, as their name suggests, grow on the ground.

Some Myths Dispelled

With the growth of orchid fever in the Victorian era came widespread myths about the plants that seem to have persisted. Orchids are not, as some people believe, carnivorous. They do lure insects to aid pollination but certainly do not feed on them. Not all orchids are jungle plants either. They can be found growing in sand, bogs, tundra and snow. They grow both at sea-level and in altitudes of around 4,300 metres (14,000ft). In Australia some species have even been found growing underground! Orchids then are fairly tough and resilient, though they may look fragile. Many varieties can be grown on a sunny windowsill, and all can provide you with a spectacular display of flowers.

A sunny window can provide an ideal showcase for many orchids. Fine-textured net curtaining will filter light.

Planting Orchids in Pots

Place plant in a pot with just enough room for the roots. Too much moist compost round roots leads to root rot. Spread out roots gently. Carefully insert compost round and between roots so that the plant is firm.

Terrestrial orchids, for example Pophiopedilum, must be potted in a well-drained mixture, but one capable of retaining moisture so that the roots can take up both water and nourishment. Use a proprietary orchid medium. Place the plant in a relatively small pot. Gently hold it by its leaves, the base level with the pot rim, and pour the compost around the roots. Tap the pot to settle the medium. Do not press down the compost.

Hanging Containers

Orchids which are epiphytes can be cultivated in a wicker basket, a slatted basket, a raft (square, wooden basket) or, most natural of all, a piece of bark. Place a pad of sphagnum moss at the bottom of the basket. No additional drainage material is necessary because of the open nature of the basket. Using the same medium and method as for terrestrial orchids, carefully pot your plant. Rafts made of teak are ideal because the wood does not rot. Place your pad of sphagnum moss in the bottom, and pot using the method already described. Water thoroughly when potted and then no more until new roots can be seen.

Light, Temperature and Humidity

The beauty, diversity and adaptability of the orchid makes it a popular choice for the greenhouse, conservatory and home. Compact-growing types are ideal for a windowsill.

Light

Even though most orchids need plenty of light, too much direct sunlight on a hot summer’s day can prove harmful. If your plant is on a window ledge remember that sun through glass can scorch it, so diffuse the light by providing net curtains. Certain types of orchid, such as Paphiopedilum and Phalaenopsis will not tolerate any form of direct sunlight. These orchids thrive best on a north-facing, double-glazed windowsill in a centrally heated room.

Humidity and Temperature

All orchids need warmth, moisture and humidity to grow and thrive. Providing humidity in the home can be a problem. No one really wants wet towels hanging about with a fan blowing the evaporated moisture towards the plant! And room humidifiers can be very costly. A simple solution is to fill a waterproof tray with 5cm (2in) of clean, pea-size gravel. Pumice is even better because it is porous. Add 2.5cm (l in) of water and maintain this level.

Raise the plants off the stones, either by covering the tray with stiff wire mesh and placing the pots on top or by standing your plant on an inverted flower pot. Make sure your plants are in a draught-free position but ensure there is ventilation.

It is difficult to pinpoint an exact temperature for all orchids. They can be divided into three temperature types: warm, with minimum night temperature of 15.5°C (60°F); intermediate, 13°C (55°F); and cool, 10°C (50°F). The maximum day temperatures are much higher, and you should ask about the temperature demands of the species you wish to grow and be sure you can reproduce them in your home.

Watering and Feeding Orchids

Few orchids enjoy permanently moist compost – allow it to become almost dry before watering – too little water is better than too much. Feeding also varies with the species, so follow any instructions carefully.

Creating Moisture for Orchids

• Fill a waterproof tray with 5cm (2in) of shingle, gravel or pumice. Pour in 2.5cm (1in) of water.
• Secure with mesh across tray or L use an upturned flower pot as a plant stand.