How do I get my orchid to re-bloom? It's a common question for orchid growers. The operative word is "re-bloom," because most people aren't growing a seedling that needs many years to mature before seeing its first flower.

	Phalaenopsis orchids, also known as Moth orchids. Click photo for larger image. Related article Orchid, other programs at Phipps

Most of the time, the answer is to give it more light, since many homes don't have enough. More important is to know what kind of orchid you have and the environment that it needs.

To meet an orchid's requirements for temperature, light and water, you need to understand its native habitat. Most orchids are epiphytes, meaning they grow on something other than soil, usually a tree branch.

It also helps to study your particular plant's growth habit. If it appears weak and limp and the foliage is dark green, light may be what it lacks. In turn, if the leaves are yellowish and very hard, the light may be too strong. Burn patches may even appear on the leaves. Be advised, though, that very limp leaves can also be the result of overwatering.

Here is an overview of the culture of the more popular orchids:

Cattleya

"The Cats," as they are commonly called, prefer intermediate temperatures of 75 to 85 degrees during the day and, like most orchids, 10 to 15 degrees cooler at night. They need strong dappled sunlight from an eastern, western or slightly filtered southern window. Your light should cast a good shadow 10 to 12 inches above the plant at least six hours a day, or 3 to 4 inches from artificial lights 14 to 16 hours a day.

A Paphiopedilum orchid, also known as Lady's Slipper. Click photo for larger image.

Cattleyas like to dry out somewhat between watering, so be sure to check the growing media each time before you water. Don't automatically water every weekend! Again, your plant's appearance will give you some clues. If the newest pseudobulbs (the swollen base of a leaf) are shriveling, the plant is not being watered enough. Also check the weight of your pot to determine how dry it is. Humidity for cattleyas should range from 40 percent to 60 percent.

Fertilizing any orchid should be done regularly, either half strength at most waterings or full strength twice a month in warm conditions. Use high-nitrogen fertilizer (30-10-10) when using bark media or a balanced formula (20-20-20) for other media. A higher phosphorus formula (10-30-10) can be used in the fall to help promote flowering. Reduce fertilizing during cooler conditions. Be careful not to overfeed. The common adage is "feed weekly, weakly."

Repotting should be done every two to three years, depending on growth. Let the amount of healthy roots determine the pot size. Orchids like to be somewhat root-bound, but leave enough room (about 1 inch) for next year's growth. Finally, good air movement is recommended.

Dendrobiums

The pseudobulb of a dendrobium is commonly called a cane, and, like the cattleya, the cane can become shriveled if improperly watered. Dendrobiums can bloom on leafless canes, so do not remove them. These orchids prefer temperatures, humidity and light similar to cattleyas, with perhaps a little more water during active growth. Let the plant dry more between watering when growth is mature.

Repot dendrobiums every two or three years, when the newest growth is 3 to 4 inches tall. Top-heavy plants that are not ready to be repotted can be placed in a larger clay pot to stabilize them.

Paphiopedilums

Commonly called Ladies' Slippers, the paphs are commonly found on the forest floor, so they prefer less light and more moisture. In turn, the humidity is slightly higher at 60 percent to 70 percent. If your home tends to be dry, the humidity can be raised by resting the pot on a tray of pebbles in water, so long as the plant is not wicking up the water. Repotting should be done yearly.

Phalaenopsis

Known as the Moth Orchid (for the appearance of the flowers), phals are also epiphytes. Their long-lasting blooms of six to nine months make them a popular choice for growing at home. Light requirements are similar to cattleyas and dendrobiums, but during our dark, northern winters, a full southern exposure is needed.

Repotting should be done every one or two years or before the medium breaks down and begins to hold too much moisture. Repotting should be done after flowering. A phal can be encouraged to re-bloom on the same flower stalk if the plant is healthy. Just cut the spike back to the third or fourth node from the base.

Phipps Conservatory and Botanical Gardens has on display its annual orchid exhibit. "Orchid Fantasy" takes its inspiration from the public parks and botanical gardens of Thailand. The display continues until March 12.