Do "CATS' go dormant?
 

Many cattleya, but not all, have a resting cycle during the winter. During this time you won't see any new growth and the plant needs much less water and very little if any fertilizer. Often this resting period is just before the plant blooms.

Mine usually glares at me accusingly before burrowing under a blanket or curling up in a very tight ball...:rofl:

As for the Cattleyas, the worst thing I've seen happen when keeping them on the chilly side is that they are then MUCH more susceptible to black rot, especially if they are kept moist. They don't really go "dormant," to my knowledge, and mine seem to be able to handle cold temps (above freezing of course) for short periods IF they are dry.

Last winter we received around 30 inches of rain and I didn't lose a single Cattleya when the temps fell well below their suggested temperatures. All my Cattleyas are mounted without any moss. In previous years I did lose some Cattleyas from rot...but those were ones that had moss. So now I don't use any moss for any of my CAM orchids.

Most of my Cattleyas lose their active root tips during winter...meaning they've gone dormant. But a few (Laelia crispa, Laelia purpurata) seem to have active root tips all year long.

When it comes to cold though...dormancy is a good thing. Florida has it rough because they have high temperatures one week and then freezing temperatures the next. Active growth is much more susceptible to cold damage than matured growth.

More and more I'm leaning towards orchids mounted without any moss being less susceptible to cold damage than potted orchids. Orchids mounted without any moss are going to dehydrate faster than potted orchids...which is a good thing during winter. A dehydrated orchid will have less water in its cells so in theory should take less damage when it freezes.

During summer I water at night so the lower evaporation rate provides the orchids with more time to fully hydrate.

Here's a chart comparing the average temps of Cattleya walkeriana and the avg temps of Galt, CA...

All of my 500+ species of epiphytic orchids are outside year around. I grow everything from a moisture loving Dracula polyphemus to a Zelenkoa onustum which grows on cactus.

Like I mentioned, I water at night during summer...this gives the orchids enough time to fully hydrate. During the day my CAM orchids are bone dry while my C3 orchids (Pleurothallis, Masdevallia, etc) stay moist enough in moss.

In order to increase my humidity I've placed large cupped bromeliads (ie Neoregelia cruenta) throughout my shade shelter area. I've also created "walls" of leafy shrubs around the perimeter.

But I've also got Cattleyas and other orchids 20-30ft up in my tree. The tree is in a wind corridor and very exposed. The orchids are all thriving though.

I was stationed in Panama for 3 years and got to spend a lot of time in the jungle. Don't remember seeing too many orchids in the jungle but on the base there were several Brassavola nodosas growing on the palm trees. I also spent a month in Roatan...a small island off of Honduras...but I didn't see any orchids there.