How to Grow Orchids Outdoors

Pink lady's slipper orchids thrive outdoors in regular soil.

In addition to their popularity as houseplants, orchids also thrive in outdoor gardens. Their slender stalks and brightly colored blossoms add elegance to gardens. Hardy, terrestrial orchids grow in regular soil, while tropical orchids live naturally as epiphytes, meaning they grip trees and grow on them. Though tropical orchids are more common, gardeners can choose either variety for an outdoor space. Tropical orchids are suited to humid areas with mild winters, while hardy orchids thrive outdoors, even when winter temperatures plunge blow freezing.

Things You'll Need

• Pots (optional)
• Chopped fir tree bark or another potting soil (optional)
• Host tree (optional)
• Cotton string (optional)

Instructions

Tropical Orchids

1. Clear a spot with bright, indirect light for planting tropical orchids. If your area is humid or cool, choose a partially sunny spot; provide more shade if the climate is dry. In the wild, tropical orchids grow beneath a canopy of rainforest trees, where they receive lots of indirect sunlight.

2. Plant orchids in pots filled with fir tree bark, perlite or volcanic rock. Alternatively, choose a tree that does not shed its bark to act as a host tree; the American Orchid Society recommends citrus trees, oaks and palm trees, as they let in enough light for orchids to grow beneath their canopies. Lay orchids against the tree trunk or a sturdy branch. Tie the roots to the tree with cotton string, which will gradually decompose over the course of several weeks, while the orchids naturally attach themselves to the tree.

3. Let rainfall gives orchids a natural watering on a regular basis. If dry conditions persist, thoroughly water potted orchids once a week, letting the water drain out the bottom of the containers to prevent soggy conditions. When growing orchids on a tree, mist them lightly with a hose or sprinkler to keep them well-watered and increase humidity, especially in the first few months after you tie them to their host tree.

Hardy Orchids

1. Choose a sunny, well-drained spot for planting hardy orchids. University of Vermont Extension professor Dr. Leonard Perry, recommends preparing raised beds or adding sand or perlite to the soil for better drainage. Unlike tropical orchids, hardy orchids usually prefer full sun, though partial shade will also suffice.

2. Avoid watering orchids when rainfall is frequent. If growing orchids in raised beds, water when the soil starts to dry. Most hardy orchids thrive in natural conditions with little domestic watering -- though wetland orchids are an exception. They require constantly moist or even drenched soil; line their beds with plastic -- complete with holes at the bottom for drainage -- to help them retain moisture. Reduce watering in the winter and during dormant periods.

3. Cover the soil with a 2-inch layer of mulch made of straw or pine needles. This helps the soil retain moisture and prevents weeds from growing.

Tips & Warnings

• When attempting to grow tropical orchids in a dry climate, place orchids near each other to increase humidity.

• Never let orchids sit in soggy conditions. This can cause root rot in both hardy and tropical species.

References

• University of Vermont Extension: Hardy Orchids
• First Rays: Growing Orchids Outdoors
• "Growing Hardy Orchids"; John Tullock; 2005
• "Growing Orchids in Your Garden"; Robert G. M. Friend; 2004
• American Orchid Society: Growing Orchids on a Tree