Orchids as Houseplants

Orchids as Houseplants
Author: Sandy Vanno, Master Gardener Warren County CCE

Orchids are beautiful indoor plants. They make wonderful plants for decorating the home. The flowers are colorful, unique, and long-lasting. They have a reputation of being difficult to grow indoors, but by selecting certain species and providing the proper environmental conditions, success is almost guaranteed.

There are many species of orchids, but the Phalaenopsis (Phals) orchid, commonly called the moth orchid, is the easiest to grow indoors and most widely available at nurseries and big box stores. Since they typically grow on trees and are located in the shade of the warm and humid tropical forest, to duplicate these conditions, provide low light, warm temperatures, moist growing mix, and high humidity.

In the home Phalaenopsis will do best in an east or west window during the winter; keep out of the direct sun, especially in the summer months. The temperature for these orchids is a minimum of 60°F at night and a maximum of 85°F during the day. If your house is about 65°F during the winter and 75°F during the summer, they will be very happy.

Phalaenopsis orchids require a relative humidity of 40-60 percent. Unfortunately, the humidity levels in most homes during the winter months are well below this range. To remedy this need for humidity, place the plant on a tray or saucer filled with pebbles and water. The bottom of the pot should be kept above the waterline. The evaporation of water from the tray will increase the relative humidity in the vicinity of the plant.

Orchids should be watered well and then allowed to dry slightly between watering. They are susceptible to root rots and death when watered too frequently. Be sure not to get water into the growing tip, or newly unfolding leaves, as it will cause your orchid to rot. Water the orchid more frequently when plants are actively growing and during bloom.

Orchid potting mix should be a very open, well-drained mix that does not dry out too quickly. There are many mixes on the market so choose one that drains rapidly but does have some water holding capacity. Growing media with bark as the primary component (orchid bark) generally works well. Most orchid potting mixes do not have enough fertilizer in the media, so fertilization of the plant is necessary. A water-soluble houseplant fertilizer used at one-half of the manufacturer's recommended rate once or twice a month is adequate.

Repot orchids only when the roots appear to be almost bursting out of the pot, typically every two or more years. If the roots have attached to the pot or old bark medium then soak the plant for a long enough period that they can be gently pried off without damage or breakage. Cut off any dead, discolored, or damaged roots, and rinse away the old degraded bark from the plant. If replanting into a larger pot, suspend the plant over the larger new pot and gently fill in around the bottom roots with new bark until the plant sits on top. Water the newly repotted plant to further settle the new bark around the roots.

Phalaenopsis has thick leaves, and usually have one or more “spikes” of softly rounded blooms that resemble a moth. The blooms can be 1-2 inches in diameter and will vary in color from clear whites, rich yellows to deep purples. Once the plant is blooming it may provide color for 4-6 months. Prevent bending of the flower stalk by placing a rigid, thin stake made of bamboo, wood, or metal beside the stem that needs support. Push it into the growing media being careful not to damage leaves or roots. Secure the flower stalk to the stake loosely with small plastic clips or plant ties. After flowering is over, cut off the spike at its emergence point. Some orchids, including Phalaenopsis, can be stimulated to flower a second time. To encourage a second bloom, cut back the flower spike to just above where the first bud was produced on the original flower spike.

If you provide orchids with adequate light, water, and fertilizer, they will produce spectacular flowers about once a year, maybe more!

References:

Wisconsin Horticulture Division of Extension

Penn State Extension

Michigan State University Extension

Iowa State University Extension and Outreach

University of Maryland Extension

Last updated November 9, 2021