The first thing is to be sure to select orchid plants that will do well in the light where the tree is located. Match the orchid to its environment. Some orchids (lady’s slipper) do well in the shade, others  (calopogan) need 12 hours a day of sun. Choose a tree that lets in plenty of light. Trees that have rough bark are the best ones to use but it’s not a must.

Put the plant directly on the south side of the tree trunk or limb about 1/2-3/4 of the way between the ground and the lower branches of the tree.  Don’t use any  sphagnum moss other medium because this would encourage the roots to grow into the medium and not attach to the tree.

Tie the orchid to the tree  with cotton string in the spring. I like cotton because it eventually decomposes about the same time as the orchid has attached itself to the tree; this occurs in about a year. Check the ties regularly to be sure they haven’t gotten too tight and loosen if necessary.

Water or mist the orchid roots daily. Since the roots are exposed, with no medium to hold moisture, they will need more frequent watering than if they were in a container.

Put orchid plant food in your spray bottle, diluted according to the instructions, and mist monthly while the plant is actively

Remove the string once the roots have attached to the tree. Once established, orchids on a tree are very easy to care for.