Orchids

These Beauties Are Not As Delicate As They Look

Orchids make up the largest species of plants in the world.

There are some 20,000 different orchid species and another 100,000 hybrid varieties. One out of every 10 plants in the world is an orchid.

Orchids have been found growing in practically every corner of the earth — from the Russian tundra to the treetops of the tropical rainforests. They grow in all sorts of diverse and difficult conditions.

Yet because of the dainty and delicate appearance of the blooms, orchids are usually seen as finicky plants to grow. In reality, they are hardy and resilient plants.

Like any other plant, orchids do best when given the conditions that most closely match their native environment. Since orchids come from so many different areas, those conditions vary from type to type.

Give ‘em humidity

If there’s one common thread, it’s that almost all orchids like it more humid than your average house plant — about 50 percent humidity.

Orchid growers often suggest placing orchids on a pebble tray filled with water almost up to the top of the pebbles. Some also advise daily misting of the leaves.

Two other good options are to use a humidifier — especially in winter — to raise the humidity in the entire room or to grow orchids under grow lights in a naturally humid basement.

Most orchids grow best in fir bark, charcoal or cork. That’s because the most popular tropical types grow naturally in trees with their roots exposed.

Although orchids like humidity, they don’t like sitting in water. The No. 1 cause of orchid failure in the home is overwatering.

One way to avoid trouble is to soak your orchid pot in the sink for about 20 minutes about once a week and then let the water drain well.

Feeding and Blooming

There are two main schools of thought on fertilizing. One teaches high-nitrogen feedings, such as 30-10-10, for the first half of the year and bloom-inducing high-phosphorus, high-potassium feedings, such as 10-30-20, during the second half. The other school (including us) professes balanced fertilizer all the time, such as 20-20-20.

The American Orchid Society recommends feeding half-strength every two weeks during the growing season (spring through early fall) and half-strength every three to four weeks at other times.

Actually, there’s a third school of feeding that suggests fertilizing “weakly weekly” — quarter-strength fertilizer with every watering.

Most orchids bloom for four to six weeks at a time. Flowers last longest if kept in cool temperatures.

Most varieties need lower nighttime temperatures to induce blooming. There are usually three reasons why orchids won’t rebloom — they’re not getting enough light, they’re not being fed properly (usually not enough phosphorus and/or potassium) or they’ve been getting steady temperatures day and night.

Like many plants, orchids like being repotted every year or two. Spring is usually the best time to do it. You’ll know it’s time when you notice the bark breaking down into soil.

Here’s a look at the specific needs of some of the most common types of orchids:

Paphiopedilum

Flowers of the “slipper orchid” can last up to two months and appear at different times based on variety. They do not require as much light as other orchids and actually do not like too much direct sun.

They can be grown well in an east or west window. Some require a night temperature of 50 for two to eight weeks in early fall to initiate bloom. Otherwise, temperatures down to 60 degrees at night and up to 80 degrees in the day are ideal. Keep potting medium moist but not wet.

Phalaenopsis

The “moth orchid” produces sprays of long-lasting flowers in winter. A second bloom can be encouraged by cutting the flower spike just below the bottom flower after the first flower spray fades.

“Phals” prefer filtered sunlight and temperatures of 60 at night and up to 80 during the day. Keep slightly moist and fertilize monthly.

Cattleyas

These have large flowers lasting up to two months. Some varieties bloom up to three times per year.

Cattleyas like a little brighter light than most orchids. East, west or shaded-south windows are best. They prefer temperatures down to 60 at night and up to 85 during the day. Allow cattleyas to dry between waterings. Fertilize monthly and avoid cold drafts.

Cymbidiums

Flower sprays on this type can last up to two months. They appear mid-winter to late spring.

Cymbidiums require bright light and can tolerate temperatures as low as 40. They need cool nights (down around 50) to initiate blooming, while daytime temperatures up to 85 are suitable.

Allow cymbidiums to dry slightly between waterings during winter but keep slightly moist during summer. Fertilize monthly.

Dendrobiums

This is a large genus of orchids with varied needs. In general, flowers last up to two months and come out spring and fall.

They prefer filtered sunlight most of the day and temperatures of 60 at night and up to 80 during the day.

Allow them to dry between waterings, and keep them fairly dry during winter. Fertilize monthly during spring and summer only.

Vandas

Spikes of up to 12 or more flowers appear in summer and winter, if light is bright enough. The spikes appear from between the upper leaf joints.

Because of their thick, fleshy roots that like to wander, vandas are best grown in hanging baskets. Give them bright, filtered light and temperatures of 60 at night and 80 during the day.

Water often during summer and fertilize monthly. Allow vandas to dry but not shrivel in winter.

Oncidiums

Tall, graceful spikes bear many beautiful flowers that last eight to 12 weeks or longer. They’ll bloom more often than most orchids when given proper growing conditions.

They like filtered sunlight for most of the day. Temperatures of 60 at night and up to 80 during the day are best. Fertilize monthly.

Miltonias

The pansy-shaped flower of this summer-blooming orchid usually lasts one to two months. They prefer filtered sunlight for most of the day and temperatures of 60 at night and 80 during the day.

Let them dry out between waterings, and fertilize monthly.