Tip of the Week — 3/2/09

Posted in Gardening Tips on March 2 2009, by Sonia Uyterhoeven

Steaming Things Up: Growing Orchids in the Home

Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.

One of the challenges of growing orchids in the home is maintaining reasonably high humidity levels.

A drywell, while not the most effective antidote, is a common solution and one of the easiest for many houseplants. Creating one is as simple as filling a tray with a layer of pebbles and water and placing the orchid on top, making sure that the pot rests above the surface of the water. The water from the drywell will evaporate around the plants. Placing an oscillating fan so that it gently blows are over the surface will increase the evaporation.

Better yet is investing in a humidifier. The humidity levels in your home will drop down to 15–25 percent in winter; a good humidifier can raise that back up to 40 percent. This higher humidity level is good not only for orchids, but probably for your wintertime dry skin and the furniture as well. Of the many wonderful books on orchids, one of my personal favorites is William Cullina’s Understanding Orchids, which has an informative chapter on different types of humidifiers.

Some orchids, however, are more demanding and require levels of humidity that are unrealistic for most homeowners. Occasionally, I hear of people who successfully grow epiphytic orchids in slatted cedar baskets that dangle beneath a skylight in their bathroom. If you have the room and the inclination to shower with your orchids, then this is fine; but for most of us, that is not a viable option.

One solution is to begin collecting miniature orchids and grow them in an old aquarium. A friend of mine grows orchids this way and fits about four or five miniature orchids in a 15-gallon tank. Fill the aquarium with 2 inches of clean pebbles and add water to just beneath the top layer of pebbles. You are essentially creating an enclosed drywell for the plants.

Circulation is an important consideration for healthy orchids, so it is best to leave the top of the aquarium open. While this growing system increases the humidity, the enclosed case can overheat in the sun, so it is important to monitor the growing conditions.

Once all the variables are in place, you have an opportunity to experiment with growing a delightful array of miniature orchids. To create a display of different heights, turn over an empty terra-cotta pot and use it as a stand for your orchids. To learn more about this setup and for an accessible, no nonsense approach to growing orchids, refer to Ellen Zachos’ book Orchid Growing for Wimps.