Bewitching, beautiful orchids have a reputation for being difficult to grow that is not entirely deserved. Some species are extremely fussy and will only grow under the strictest environmental control, while others thrive in the same conditions found in most homes. The key to growing orchids is simply to choose the right type and provide for their needs, which is less tricky than it seems.
Choosing a Type
Moth orchids (Phalaenopsis spp.) and cattleya orchids (Cattleya spp.) are both good choices for beginner gardeners due to their forgiving nature and less stringent requirements. Spray orchids (Dendrobium spp.) are another suitable choice for beginner gardeners, although their needs are a little more specific.
Both moth orchids and cattleyas will survive outdoors within U.S. Department of Agriculture plant hardiness zones 10 to 12, while spray orchids tolerate USDA plant hardiness zones 9 to 12. However, orchids do best when grown indoors where their environment can be monitored and adjusted.
Temperature plays a key role in growing orchids because it aids flower formation. Typically, they need a 10- to 15-degree temperature differential between day and night, although their needs change with the season.
Moth orchids perform best with nighttime temperatures around 65 degrees Fahrenheit and daytime temperatures between 75 and 80 degrees, while cattleyas prefer 55- to 60-degree temperatures at night and 70 to 85 degrees during the day. Spray orchids need a 15- to 20-degree temperature difference, with nighttime temperatures between 60 and 65 degrees and daytime temperatures between 80 and 90 degrees.
In autumn, moth orchids need a few weeks with nighttime temperatures around 55 degrees to initiate flower spike formation.
All types will suffer if temperatures rise above 95 degrees unless shade, humidity and air circulation are increased.
Bright, indirect light is best for most orchids, although it varies slightly between species. Moth orchids, spray orchids and cattleyas all perform well beside east-facing windows, although west- and south-facing windows will also work for spray orchids and cattleyas if they are lightly shaded from the outside or with a sheer curtain. Avoid full, baking sun exposure because it can burn the foliage and flowers.
Bright, medium or light green leaves indicate optimum light levels, while dark, lush green leaves indicate low light.
Most common orchids originated in the tropics and, as a result, they need humidity to prosper. Moth orchids and cattleyas both need humidity levels around 50 to 80 percent, while spray orchids do best at 50 to 60 percent humidity.
The best way to maintain humidity around orchids is to set them on a tray of gravel or pebbles that is halfway filled with water—just make sure the bottom of the pot doesn’t touch the water. Misting is another choice, although too much moisture on the leaves increases the risk of fungal and bacterial disease.
Air circulation is vital to preventing disease, so keep an oscillating fan running on low near your orchid.
Pots and Soil
Healthy roots make a healthy orchid. Without the right pot and growing medium, orchids will not have access to the moisture, air and nutrients needed for healthy growth.
Grow orchids in a pot with plenty of drainage holes around the base, or in a designated orchid pot with slatted sides. Do not put them in cache pots or other vessels with poor drainage.
Choose a pot that is no more than 1 or 2 inches larger than the original pot. Avoid larger pots because the growing medium will retain too much moisture.
Use commercial orchid potting mix, or create your own by mixing 5 parts medium-grade, horticultural fir bark; 1 part horticultural charcoal; and 1 part perlite.
Most orchids need repotting every one to three years if they become top heavy, if their roots overtake the pot, or if their growing medium degrades.
Once established under the right conditions, orchids need very little hands-on care apart from regular watering and feeding during the growing season.
All orchids need regular watering due to the porosity of their soil. However, the ideal moisture level varies among species. Moth orchids must be watered when their soil is nearly dry, while cattleyas must dry out completely between waterings. Spray orchids should be kept evenly moist during the growing season.
One thing that all orchids have in common is an intolerance for hard water. Filtered, distilled and rainwater are best; avoid salt-softened water along with cold water. Saturate the growing medium and let the excess water drain off completely before setting the pot back in its place.
Fill a pitcher with water and let it sit out overnight to release the chlorine and other gases before watering orchids with it.
Most orchids need supplemental fertilizer throughout the warmer months when they are actively growing. A myriad of different feeding regimes exist, although a basic routine of regular, dilute liquid fertilizer works well for more orchids.
- Mix the right solution. Dilute 1/2 teaspoon of balanced 15-15-15 fertilizer or blooming 7-9-5 fertilizer in 1 gallon of distilled or rainwater.
- Feed monthly. Water the orchid every four weeks with the solution, letting the excess drain from the pot.
- Remove salt buildup. Run clean, fresh water through the growing medium for 10 minutes every month to flush out any salt buildup from the fertilizer.
- Avoid overfeeding. Root burn can occur if the fertilizer is too strong or applied too frequently.