In the Garden | Understanding orchids

In the Garden | Understanding orchids

By RYAN PANKAU

In recent years, orchids have become increasingly popular as houseplants, popping up for sale everywhere from smaller garden centers to big chain stores.

Many of us have taken these plants home, given them plenty of TLC, only to be let down when they begin to suffer from wilting and discolored leaves.

This has led to a common misconception that orchids are hard to take care of, requiring a special kind of green thumb. In reality, these plants are quite easy to care for once you understand their particular needs. In fact, it has been said that they thrive on negligence.

Most orchids we know as houseplants are epiphytes (like mistletoe and Christmas cactus), meaning they do not root into soil but have specialized roots that attach to other plants or rocks and absorb moisture from rainfall, humidity and dew.

They typically come from tropical environments where water is abundantly present in places other than the soil profile. Therefore, they require slightly different care than your typical houseplant.

Since their roots have adapted to absorb water quickly when it's present, they cannot handle extended periods of saturation, which often results in root rot and mortality. Overwatering is probably the most common cause of death for orchids kept as houseplants. This is hard for many to hear as they assume that their watering efforts, diligently performed with love, were beneficial to the plant.

Orchid roots need to completely dry out between watering. That is why some "neglect" can go a long way.

Orchids do require a more specialized potting mix that drains quickly and has ample pore space for air circulation. Many premade mixes are available, consisting of some combination of bark, peat moss, perlite or sand.

There is a pretty wide margin of error between just enough water and not enough to support the plant. However, saturated soil conditions can be detrimental. The easiest way to assure that you are not overwatering is to check the planting medium. If it still feels damp a few inches down, no need for water. Ensure it has dried out completely before watering again.

The amount of water an orchid needs may vary by season, especially if you move them to an outdoor location during the warmer months. In general, my orchids are not one of the houseplants I water every week; they are probably an every-other-week type schedule this time of year.

Although orchid roots cannot tolerate saturation for very long, orchid plants do love humidity. Many common houseplant species, such as Phalaenopsis orchids, thrive in 50 to 85 percent humidity, which is difficult, if not impossible, to maintain indoors in the wintertime without use of a humidifier. My home is consistently around only 20 to 30 percent humidity in winter, but we have a woodstove that greatly contributes to the dry air.

To provide additional humidity, many home orchid growers place their plants on a tray of pebbles. Water can be added to the tray, not to exceed the height of the pebbles, and the plant's pot can be placed on top.

The specialized orchid roots are able to absorb humidity from the air, much like they would in their native tropical home.

Another factor that makes orchids ideal houseplants is that they do not require a lot of light. Too much light can lead to sunburned leaves or cause blooms to drop early. Many east-facing or shaded west-facing windows provide ample light. A bright south facing room, with indirect light on your plant can be optimal.

If you are interested in becoming an orchid enthusiast, please join the University of Illinois Plant Biology Greenhouses for their Spring Fling and Orchid Sale, which runs from 10 a.m. to 2 p.m. March 10 and from 1 to 3 p.m. March 11.

"Our sale focuses on the more uncommon orchid species," said Debbie Black, the Plant Biology Greenhouse manager. "We focus on smaller species that fit indoor spaces well, versus the more common everyday varieties."

Black and other members of the Plant Biology Greenhouse staff, will be on hand to answer any questions about orchid care and help you select the perfect plant. In addition, the Conservatory and Plant Collections will be open for display. They offer a great local, tropical escape from the winter blues.

Ryan Pankau is a horticulture educator with the University of Illinois Extension, serving Champaign, Ford, Iroquois and Vermilion counties.

Sections (1):Living
Topics (1):Gardening