growing chids on trees

[Leisurely]

I would definitely include Laelia Anceps to your list if I were you. They are very tough plants, not only to cold but they don't seem to have any problems with insects and disease and would brave -1C with no problem.

Another variety that can tolerate very cold conditions for an orchid is Dendrobium nobile and it's hybrids. I recently had a plant that went through -3C and there was absolutely no damage to plant leaves, roots or buds. Since they are available in so many different colors, you could have a great display of flowers in late winter and spring. There is a picture on this forum under Dendrobium Alliance titled Cold Tolerance if you care to look.