Saturday, December 26, 2015

Caring for Orchids by Donna Duffy

Photo courtesy urbangardensweb.com

Help! I got an orchid for Christmas! If that sounds like you, relax. That beautiful orchid is relatively easy to care for if you attend to its light, humidity and watering needs. Planttalk Colorado provides in-depth information on four orchids commonly grown indoors in Colorado. Another great resource is the Denver Orchid Society.


Cymbidium orchid, photo courtesy Planttalk Colorado

Cymbidium orchids are native to tropical Asia and Australia. They are best known for their incredibly thick petals that are hard and waxy. They need typical household temperatures; 65 to 70 degrees during the day and 58 to 60 degrees at night. In addition, standard cymbidiums, or the large-flowered varieties, require a six to eight week cool period in the fall when night temperatures are at least 45 to 50 degrees, or even down to freezing, to form buds. Modern miniature hybrids do not require such low temperatures to induce flower buds; a low temperature of 60 degrees is adequate. These plants thrive in 50 to 80 percent relative humidity. Fertilize these orchids frequently when new growth is forming, generally from spring through summer. Cymbidiums bloom only once a year and the season of bloom varies by species or hybrid. Repot these orchids every two to three years when new growth begins, generally in spring.

Cattleya orchid, photo courtesy ourbreathingplanet.com

Cattleya orchids, sometimes known as queen of the orchids, are native to tropical America. Best known for their incredible array of flowers, the blossom size and number of flowers vary by variety. Cattleya orchids perform best in very high light and flowers will not form if the plant does not receive enough light. Cattleyas bloom only once a year, but the season of bloom varies by species or hybrid. They grow well in typical household temperatures, about 65 to 70 degrees during the day and 58 to 60 degrees at night. These plants will thrive in 50 to 80 percent relative humidity. Use a commercial, water-soluble orchid fertilizer every month and repot orchids every two to three years when new growth begins.

Phalaenopsis orchid, photo courtesy Planttalk Colorado

Phalaenopsis orchids, commonly called moth orchids, are named for gently arching, flowering stems with flat flowers which resemble moths in flight. These orchids like moderate to low light situations, such as an east or north window, bright diffused sunlight, or broad-spectrum fluorescent lights. Keep the potting mix evenly moist and let it dry slightly between waterings. These orchids also like typical household temperatures of 65 to 75 degrees during the day and 55 to 60 degrees at night. Encourage mature plants to form buds by giving them two months of evening temperatures down to 50 degrees in the fall. These plants will thrive in 50 to 80 percent relative humidity. Repot these orchids every two to three years when new roots begin to develop. When new growth is forming, fertilize these plants monthly. Don’t move or prune once buds appear. Phalaenopsis generally bloom only once a year, but the season of bloom varies by species or hybrid. Flowering stems will usually produce secondary flowering stems if cut back just below the first flower.


Paphiopedilum orchid, photo courtesy Planttalk Colorado

Paphiopedilums, commonly called lady slipper orchids, are native to tropical Asia. They are perhaps best known for their leaves, which are sometimes mottled or patterned, and unusual, waxy flowers which are striped, spotted or solid in color. These orchids perform best in moderate bright filtered light to low light situations, such as an east or north window, or in diffused sunlight or under broad-spectrum fluorescent lights. Paphiopedilums have fewer roots than other orchids and are very susceptible to root rot, so it is important that the potting mix drain very well. Do not allow to dry out. Plants with patterned or mottled leaves like temperatures at 65 to 70 degrees during the day and 58 to 60 degrees at night. Plants with plain green leaves generally require cooler conditions. These orchids will thrive in 50 to 80 percent relative humidity. Paphiopedilum are light feeders; when new growth is forming, fertilize monthly. Paphiopedilums generally bloom only once a year. Repot these orchids every two to three years when new growth begins.