Replace walkin greenhouse cover with 40-60 %shade clothe

[Roberta]

Tolumnias definitely need be warm. They won't do well with winter. Catts, it depends. Many Catt species (and their progeny) do fine through winter where we live. Warm growers like C. dowiana and lueddemanniana don't. A lot of Oncidium types do fine outside, some need warmer. So... again the answer on those, "It depends on which ones". There are some orchids where you can generalize about conditions based on genus, knowing that there are always exceptions... Phals and Tolumnias are pretty much warm growers. Cymbidiums (except for a few Asian ones like ensifolium and sinense) are pretty much cool growers. But for most genera, you have to dig down to the species level to know what they want... or what you can get away with, short of the ideal.