I SHOULD but I don't necessarily do so. I'm only orchids for the last few years and haven't killed enough yet to stop me from trying to get the Masdies to live in the same gh as the Catt hybrids.

I DO keep the Masdies in more shade, and lower in the gh to try and fudge the temp differences a bit.

That is pretty much how it goes.
Depending on your setup and natural climate, the GH interior environment will provide a certain climate band.
It is then up to you to select orchids that will do well within that climate band. Anything outside of that climate band (cooler or warmer requirements) might not do so well in the GH unless you set up a special "mini-greenhouse" within the GH to accomodate the orchids with special needs.

Consequently, it would be difficult to keep cool-growing orchids in the same GH as warm-growing orchids. It will be nearly impossible for the size GH we have to keep one section cool while the other stays warm.

There are so many orchids available though, that you should find plenty that you like that would fall within your GH's artificial climate band.

In my case for example, the GH tends to be on the warmer side so I can keep Cattleyas, Dendrobiums, Cymbidiums and some other warm/moderate orchids.
Any cool-growing orchids are pretty much outside of my climate band.

Hi
IME the warm growers are much more tolerant of cool than the cools are of warm.Don't forget many species need winter cool downs to flower well. Those would be good choices as it would definitely help with the heating bill.
For GH growing I'd select from those that would fit into your yearly averages. Whatever band of temps is easiest to maintain. keeping it as cool as possible during winter.
Start with these and then experiment into others.
Or do what I did buy some that won't tolerate your climate kill them, try again,kill them and then discover there are thousands of species that would love to grow in my area. Not the most economucal route lol gary

EEEEEEEEEEK! I don't want to kill any of my orchids. I have an Ocidium but the rest are catts, dens and phals. I'm wondering if I should keep them in my sunroom or winter them in the GH this winter. We're going to try to keep the Rion around 55 to 60F at night. I'm not sure what the day temps will be. The little HFGH would be around 100F by the time I got out there to open the vents last winter.

I dont have that much experience with oncidiums, so I cannot make any statements about how they will behave to the temperature range in your GH.

The phal will probably need to stay indoors. They dont like any significant temperature swings. And the GH might be too bright for it too.

However, If you can keep the GH temps between 50F (nights) and 90F (days) [actually, closer to 80F would be better] the cattleyas and dendrobiums will like it there. Just provide adequate humidity, water and air circulation during the warm seasons.

If they are all growing indoors right now in a climate controlled sunroom, you will need to slowly acclimate them to the new temperatures if the GH temperature band is different.

Cattleyas and Dendrobiums like a LOT of air circulation though, so make sure that your GH has a couple of strong fans that really agitate the air.

I posted a question similar to yours a while back, but it was regarding light requirements among a very varied orchid population in the gh. If you have very disparate plants, it is difficult, but there are a lot of hybrids which have been cultivated to put up with "the rest". Within the gh itself, it is possible to create areas which can accommodate outsiders.
I am currently trying to set up areas within the gh for plants in groupings of light, heat, and water preferences. It's not easy, but I have only a few cool growers; most are intermediates.
IMOH, light is the most important factor (Hello, Howard!). Finessing the rest takes a lot of observation, but I think it pays off.
Ann

I think the cool growers will be outside my temp range also. I know when the winter sun hits the new GH it's bound to hit 90 to 100F before I can get out there to open the vents. If I leave the auto-openers operating I fear the heaters and vents will be fighting it out every day. Do you leave your auto-openers operating all winter?

Because of the fan in the little HFGH last winter the heat stayed pretty even. I had the ferns and impatens on the gravel where I hoped it was the coolest. They thrived, even with the low humidity. My precious orchids were in the sunroom. :^)

You're a hoot! :-D We have two small heaters for the 8.6 X 16.6 Rion. Also two HAF fans plus one for the floor to keep the air on the floor moving. We'll remove the shade cloth when it cools off here, usually mid October some time. We're hoping to keep it around 60 F at night to accomodate not only the orchids but the other "obsessions" I grow = cacti, succulents, geraniums and impatens. I also have a small collection of tropicals. The few nights last winter that dropped into the low 50s didn't seem to bother these plants - they kept right on blooming!

I think I'll keep my precious orchids in the sunroom until I know what the temps will be in the new Rion this winter. I don't want to lose any. I lost almost my whole first collection to a storm a few years back. It was heartbreaking. I had phals and dens that had bloomed for years.... :*(

I have a kerosene heather in case the juice goes out during the winter.

All my orchids spend the spring, summer and fall on the front porch outside. It's open on three sides. All get a few hours of sun except the phals. They're in a spot where they only get dappled sun through a cherry tree.

One den is in full bloom and another is full of buds. I think I'll bring them in as usual in the fall until I see that the heaters are adequate for the GH on a really cold night. It can drop to the teens here in the winter.

We're going to put the bubble wrap on the north wall and ceiling in hopes it'll help on those bitter cold nights. I think we're stuck with using duct tape to hold it on.

The way my GH is set up I can easily shade a small section for shade lovers. As soon as we have all the tables etc. in there and it's finished I'll take more pics. Keeping the humidity up will surely be a problem as it was in the HFGH last winter. Because of the limestone rock we can't run water to the GH and my husband doesn't want hoses left with the pressure on. I would drag the hose to the HFGH almost every day and wet down the gravel floor and some of the plants. But in hours the humidity was back down to 20 to 30%. I had a pump sprayer with clean water I'd use on some of the plants and ferns. Nether really made a big difference. I have a cool mist vaporizer I plan to try this winter in the Rion. It puts out about 6 gallons per 24 hours.

I have one Oncidium (alongside a Blc and a few Dents) that has done so well at the same height , but with a bit less light,that I've had to divide it twice in a year. The one small sickly plant that was given to me midsummer 06 is now four plants, two in pots and two mounted.

greenhouser - My orchids did fine over the winter with night temps (inside the gh) as low as 53 on several nights in a row...day temps to mid-high 60s. I'm NOT claiming that the temp was ideal, but those that went through that period seemed to have no obvious trouble developing new growth or blossming.

Thanks. This is good to know. :^) I almost can't wait for fall to start moving my plants in there. My geraniums do so much better in a GH than outside. You should have seen the blooms last winter! Large flower heads with as many as 6 on some plants. My HFGH was like a tiny paradise. I'm anticipating the plants to do even better in the Rion.

I'm also growing weary of the summer heat. It always happens about this time of year. Oh for those nice brisk days of fall.......

Hi
I grow my orchids both within the shadehouse and attached to trees in the yard.. I get to lear what can be tolerated this way.lol The only time I panic is the thirties?? Most but definitely not all orchids will tolerate this in fact quite well. Check on your phals as to the species some appreciate a cool down while other require a warm up to flower well. Generally the pinks and whites like it cool while the yellows and mottleds are in reverse.
There relyy is no other way to find out what will do well for you except by experimenting.
Since you have such a varied climate you'll have great variation no matter what you do.
Even in my area this is a profound problem though obviously not as profound. gary

I too am in Middle Tennessee. Last year was my first winter in my greenhouse. I only placed a few Phals and a Dend hybrid along with all my tropicals. I didn't run the risk of killing all my chids. I monitored it daily (kept temp and humidity levels) and have a better idea of how the winter went last year as to what I am going to do this year.
I will probably place all my Phals in there so they can get the cool down they need to bloom and may try a Paph or two.
I am going to insulate the north wall and roof this year. Right now it is double poly walls and I had to run two heaters and fans and leave the auto vents on auto last winter. It was tough trying to regulate temps as my greenhouse is 8 x 12. I asked a lot of questions on the forum and then jumped in there and aired on the side of caution.
Let me know if I can suggest anything. One thing I did do was visit another greenhouse (commercial grower in Franklin) and he gave me a lot of useful information that I wish I had known before I had ordered my greenhouse.
Cindy

These are the mottled and a yellow Phals. The dens are shades of lavender and purple with one white w/purple throat. The little catts are all colors (from HD). They're really thriving on the front porch.

The dens are oddballs since some bloom in the winter, around the holidays and one is blooming now in the heat of summer. I can't recall the color of the Ocidum as it's a survivor of the storm that destroyed so many of my Orchids.

Wow am I glad to find someone from TN on here. :^) I know Franklin, although not that well. I'm about 30 miles from there. What is the name of the commercial grower there? I would love to check them out.

I have 2 small heaters from Wally World in the Rion and 3 HAF fans. I'm hoping they can keep it at least 55 on the coldest nights. We're bubble wrapping the north wall and part of the roof. Last winter, with no extra insulation one small heater kept the little HFGH in the low 50s on those bitter cold nights. I had it on 1200w so the fan could also run and not flip the breaker.

What GH do you have?

I'm about 45 minutes out of Franklin, more south. I purchased my greenhouse from Morton's in McMinnville. They have been at the Lawn and Garden Show many times and I had my eye on "Granny's Greenhouse" for years and finally was able to pruchase it.
The orchid grower is Stones River Orchids. He is a hard man to find and I have his ph number and address if you wish to call him, just email me. You can only visit by appt. only and it is worth the trip. He is a grower/hybridizer of Phals but has others for sale as well. He also is a judge at many shows that I have been to. I don't show as I have only been loving orchids for around 5 years now. I just love going to the shows in Memphis and Nashville.