Brad Carter of the UCI Arboretum in Irvine offers the following tips on growing orchids in trees:
* Select a species that can grow with roots exposed. He recommends species of Oncidium or Encyclia orchids.
* Remove the plant from its pot and gently shake the bark from the branch.
* Select a strong, vertical tree branch at least two inches in diameter. Position the plant so the new root growth is in the direction of the branch. Wrap nylon filament such as fishing line several times around roots and branch. Secure the plant by also wrapping one or more stems to the branch.
* Wet some sphagnum moss, place around roots and secure with nylon filament. The moss protects the roots and retains water.
* Slugs and snails will eat orchid roots, and sow bugs may also climb trees to devour the moss and root tips. To combat them, scatter granular Sevin on the moss.
* Maintain the aerial orchids by watering once or twice weekly in cool weather and at least two or three times weekly in hot weather.
* Fertilize in early spring, late spring and early summer with a water-soluble balanced fertilizer applied by hose and hose-end sprayer.