How to Grow Orchids


Dianne Westlake

The most readily available orchid is the Phalaenopsis or the moth orchid. It has large glossy, flat, elongated leaves and arching spikes of large white, pink, striped or yellow flowers. The flower spires can become so heavy that mechanical support is required. Support can be purchased or a piece of heavy weight wire can be bent and inserted carefully following the inner edge of the pot. Flowers will last for an extended period of time but when the flowers fade, do not cut the stalk back. Usually a secondary stalk will grow allowing you to enjoy a new flush of colour. At this moment I have 7 of my 10 Phalaenopsis in full bloom with new flower spikes forming in two others. What a beautiful display of colour from deep pink to pale yellow and white with an array dots and swirls.

To successfully grow these orchids you need to provide the conditions that approximate their natural habitat. Heat, light and humidity are the three most important factors. To provide the best conditions we need to think of where they grow in nature. They live in trees where they get constant fresh air movement around their leaves and roots. Frequent light rains provide nourishment to the roots and bacterial problems are avoided because the air movement allows the plant to dry rapidly. On a recent trip to Cuba, we were given a demonstration of how to divide and grow orchids in an incredible fern garden in Santiago. The technique involved using copper wire, which has an astringent effect, to attach the plant to a tree branch. The warm humid air and misty rains provide all the nurturing the young plants require. What a shock it must be for these orchids, to have the roots stuffed into a dark pot filled with growing medium,

Phalaenopsis enjoy much the same temperature range as we do. Night temperatures in the range of 16-18 C (60-65 F), and daytime temperatures around 24-29C (75-85 F) are optimum but occasional deviations will be tolerated except when buds are forming. Chilly temperatures may cause the plant to stop budding. A day/night difference of 6-12C will aid flower formation. If a healthy, mature plant fails to bloom, try to provide slightly brighter light and lower night temperatures (14C nights) for the month of October.

Indirect sunlight is best and caution should be used when placing a Phalaenopsis in direct sunlight. Its leaves burn easily from too much exposure to the sun. If you choose to place your Phalaenopsis outside for the summer, be very cautious. As with all houseplants, start in the shade and very slowly move your plants to brighter light.

I use a fertilizer formulated for orchids that I mix half strength and apply alternate weeks. Between applications, I flush the pot with plenty of room temperature or warmer water to remove any build up of salts from our hard water and fertilizer and allow the pots to drain thoroughly before returning them to their saucers. Never use chemically softened water. Normally, watering once a week is sufficient to keep continuous moisture just below the surface of the medium. More frequent watering in necessary in winter but be cautious of over-watering.

Orchids flourish in moist air, with a humidity level of 55-75% being ideal. Place your plant over a tray or dish of water to help increase moisture. A layer of pebbles or small stones will raise the pot to ensure that it does not sit directly in the water.

Healthy Phalaenopsis start with healthy roots. Roots often grow over the side of the pot and up into the air. Leave these roots on the plant, perhaps misting them when the plant is watered. After flowering is the best time to repot. While your orchid probably came potted in moss, I always use a medium bark mixture that I soak for an hour or two in warm water before using. Gently remove the plant from the pot, disturbing the healthy roots as little as possible and remove old medium if it is loose. Inspect the roots carefully and cut any dead, damaged or diseased roots with a clean tool. The Phalaenopsis can be returned to the same pot (after a thorough cleaning) as the plant grows upwards without spreading. The pot should only just hold the roots of the plant. Position the base of the bottom leaf at the surface of the medium and center plant in new pot. Carefully put new media into the pot, and around the roots. In order to allow the plant to heal any root damage, and prepare to start a new flush of root growth, do not water for a week or two.

Once you have mastered growing the Phalaenopsis, it is time to branch out and try some of the other orchids.