Everything you need to know about growing orchids at home – Chicago Tribune

The Garden Orchid Show inspired me to try growing orchids at home. Can you give advice on where to start?
—Jose Alvarez, Highwood

Moth orchids (phalaenopsis) are among the easiest orchids to care for at home and are easy to find in stores and garden centers. Moth orchids prefer a warm environment of 70 to 80 degrees Fahrenheit during the day and above 60 degrees at night. This is where most of us keep our home. Moth orchids should not be kept at temperatures above 85 degrees and below 55 degrees. Phalaenopsis species and varieties do not need much light to grow well. They do best with indirect light, so avoid direct sunlight to avoid leaf burn. Try a bright, east-facing window or even a west- or south-facing window as long as the light is indirect. A north-facing window may not provide enough light, so move your plant elsewhere if it doesn’t do well there.

Moth orchids are typically grown in a bark mixture containing sphagnum moss or another medium to help retain water. A pure bark medium can dry out very quickly, while a pure sphagnum moss medium retains water. Monitor your orchid carefully to prevent overwatering. Replace orchids with fresh growing medium every two to three years. The best time to repot is when you see new root growth; This way the new roots can quickly adapt to the new potting medium and you are less likely to damage the delicate root tips. For plants in pots 5 inches and larger, use a medium grade orchid bark mix. Feed the moth orchid with a diluted, water-soluble fertilizer a few times a month when you water it during the growing season. Stop fertilizing during the winter months.

Water your moth orchid with rain or distilled water early in the morning as the mixture nears drying. Try not to use water softened with a water softener. Overwatering is a more common problem than underwatering. The planting medium should be allowed to dry slightly between waterings, but should not be left dry for long periods of time. In general, water an orchid planted in bark once or twice a week, less frequently if planted in moss. Your home environment should affect watering frequency.

Orchids can bloom two to three times a year, with flowers that can last for more than two months after the plants reach a mature size. Most of the time, you can encourage a second bloom from each spike with timely pruning. When the last flower on the spike has faded, examine the spike spot for small fleshy bumps or knots. Count three nodes from the base of the ear (count only the nodes with green flesh and ignore the dried ones). Cut the nail 1 inch above the third knot. If your plant is healthy, this process should awaken one or two of the nodes to produce a new spray of fresh flowers. A new flower stalk should emerge from the upper node within a few months. If there is no response or the flower stalk turns brown, cut back near where the plant emerged.

For more plant recommendations, contact the Chicago Botanical Garden Plant Information Service at plantinfo@chicagobotanic.org. Tim Johnson is senior director of horticulture at the Chicago Botanical Garden.