running "Cats" cold
 

Hopefully other will know more than me, but I would have thought 40's was too cold for Catts. They might go into a dormant state and I guess might die if if that lasts too long. At just below 40 you risk cell damage if it freezes.

I can't say for certain though. I always bring my one and only Catt into the house from the greenhouse (which I keep about 42 over the winter) when the weather gets cooler. They probably go down into the 40s at night a little bit before I bring them in but not for long periods and probably only mid 40s.

Most of my Catt alliance (mostly intergenerics) are outside, and take overnight low temps in the 40s without apparent problems (down to just below 40, on a sheltered porch, and out of cold rain!) - might be less than ideal, but certainly none have died - I don't know if it has slowed growth, or not, but spikes definitely grow very slowly! :p Day time temps in winter usually range from mid 50s - mid 60s. If I had any I knew to be 'hot' growers, I'd probably be more careful with those, temp-wise.

better to keep them at 50 or over to get any kind of growth and flowering.....some catts can take short periods of 40 with no harm, and others will sulk if left at 40....i dont think they ALL would die if exposed to temps that low all winter, but it sure wouldnt be good for them.....

Shock would certainly set in. Imagine you being suddenly loaded with cold water when you expected warmth.

Why do you want to do that?

Danny, it probably depends on the cattleya. Most appreciate anywhere between the mid to high 50s at night, especially during the winter dormancy. Some species, however, wouldn't be bothered too much by occasionally dipping down into the 40s, especially if kept dry. C. percivaliana, C. candida (AKA C. chocoensis or C. quadricolor), C. walkeriana, C. intermedia, C. loddigesii, C. mossiae, C. schroderae and C. nobilior (in my experience) are all quite hardy regarding their temperature tolerances (as are, to a lesser extent, C. amethystoglossa and C. bicolor). The ones I wouldn't want to try subjecting to cool temperatures are C. dowiana, C. warneri and C. lueddemanniana. May I ask why you would be interested in subjecting your cattleyas to the lower end of the cool range that you referenced? Just curious...

Steve

running "Cats" cold
 

Last winter my GH regularly got down into the 30s due to the extreme cold we experienced. I just could not keep it warmer at night. I daresay none of my plants suffered greatly. I have a great many plants in the Cattleya family along with other genera. Now whether this delayed their flowering or other development, I cannot say. I would rather keep the GH warmer if I could but sometimes I can't.
My problem is more with the extreme heat we are experiencing right now. I AM losing plants, especially the thin leaved ones, to the heat. My plants are all kept outdoors in the summer. Some seem to do OK in the heat, others are suffering.
Beverly A.

I keep all of my catts outside year round. I have seen it get down into the mid 30's quite often with zero problems.... But I only grow temp tol. plants. The only thing I worry about when it gets that cold is root rot. Keep your plants on the dry side in the winter.

Steve,
I've made a list of your suggestions. I guess I am the inquiring type. But the truth is I am building a greenhouse and don't know if it will be done by the time cold weather sits in. Annnnd I'm also the type that puts the "cart before the horse" and I've already bought a couple of hundred plants.
So now the realization sets in.
Thanks for the info.
Danny Medina

De ja vu!

I did just that last summer! My greenhouse took until May of this year before it was ready :((

For ten months I had my hundred or so plants stacked in the kitchen under lights with fans and humidifiers...95% catts

It was a tough go. The main issue for me indoors was humidity not temperature.

Not sure how humid your climate will be outside for your plants. I am relatively certain that most of your plants should survive the lower temps to the forties IF they are acclimated. This means having them outdoors when the weather is "great" and letting them gradually experience the climate temperature decrease. I do agree with the exception of some of the warmer species like C. dowiana.

You will need to be watchful of "cold snaps".

Good luck!