Here in relatively frost free South Florida, orchids can be successfully grown outside all year. Orchids can be naturalized onto trees where they can take root and develop, just as they do in the wild. Cattleya, Phalaenopsis, Dendrobium, Oncidium and Epidendrum orchids are all great choices to attach to trees in your yard.
Remove the orchid from its pot and remove any loose potting material, its roots then can be firmly secured to a branch or trunk of the tree. As the orchid grows, new roots will extend out and attach themselves to the tree bark. This will add interest and color to a tree in your landscape. Orchids live on trees but take no nourishment from them. Choosing the appropriate tree to fasten the orchid to should be considered. Most orchids require partial shade for optimum growth and flowering. High light intensities can cause the orchid foliage to yellow or burn. Recommended light levels for orchids is 70-80% shade. Phaelaenopsis however, thrives in 85-90% shade.
Orchids attached to trees must be watered regularly. Rain may do the job at times, but please don't always depend upon Mother Nature. The orchids can get nutrients they need naturally from falling tree debris as they would attached to a tree in a rain forest.
If you have any orchid growing questions contact Master Gardener Volunteer Hotline at the UF/IFAS Extension Palm Beach County 233-1750 M-F 9AM to 4PM.