I read in a few places that orchids are devided into cool, intermediate or warm growing by their minimum temp tolerance(can't remeber those exact temps right now). does anyone know the max temp in each catagory?

Hey Amber

It's been a while and no one else has put there 2c in so I thought I'd chip in. Here in Oz we have arctic through to tropical climates (cold/cool through to hot). We also have a number of genera and species which come really close to bridging those environments. Den speciosum is a notable member of that group.

I have one particular Den kingianum that grows beautifully but won't flower unless it gets sustained night time temps below 5 degrees C in Winter.

Are you worried about the ability of your plants to survive in temperatures there?

Cheers
Stephan

Stephan, thanks for the bump, I'd meant to look this up and it had slipped my mind. Found this googling, hope it is what you were looking for. (FWIW it put strap leaved paphs in the cool section, but I tend to grow mine intermediate.)

COOL
Max Day 80F (27C)
Min Night 50F (10C)

INTERMEDIATE
Max Day 85F (30C)
Min Night 55F (13C)

WARM
Max Day 90F (32C)
Min Night 60F (15C)

It is interesting to me that not all sources agree on these temps. For instance, Jay has a different set at: http://orchidspecies.com/ and I remember seeing a chart in the Ortho Orchids book that differed from his. What it shows me is that orchids are very adaptable, all things considered.

thanks everyone!
phragfan has just proved my point that the issue is usually the min temp rather then the max.
where I live night temps seldom go below 55F but I do have a problem with day temps in the summer.
I'm fairly convinced now I'll have to give up on most of my oncidium hybrides. they all suffer greatly during the summer and look very bad. :(
luckily, all my "cool growing" paphs are ignoring the charts and doing great during the hot days (provided they are being watered almost every day).
thanks again!
amber

thanks everyone!
phragfan has just proved my point that the issue is usually the min temp rather then the max.
where I live night temps seldom go below 55F but I do have a problem with day temps in the summer.
I'm fairly convinced now I'll have to give up on most of my oncidium hybrides. they all suffer greatly during the summer and look very bad. :(
luckily, all my "cool growing" paphs are ignoring the charts and doing great during the hot days (provided they are being watered almost every day).
thanks again!
amber

I can see why Israel would be a place difficult to Onc. There are some warm growing ones, but most like a good deal of humidity. If you could somehow increase the local humidity, and have lots of air movement, you might be able to grow some.

I personally think cool growers can go down to 35F......that include cool growing catt hybrids, australian native of various kinds, masdevallia's, Odont's, some paphs, Phrags, Dracula's and others I have forgotten. I grow all these outdoors down to 35F and they do fine.

So I think Cool is cooler than 50F.

That's just my opinion of course.

I have read from numerous sources, that for particularly the cooler growing Paphs, once the temperature gets above 28oC, they shut down and stop growing. I think the multi-florals and mottled leave Paphs can go to early 30'oCs without a problem. If your temperatures in summer are regularly in the mid 30oC's or higher you have a problem. Particularly if this is combined with low humidity. I think keeping your maximum temps at 28oC or below would be ideal for a mixed collection of Paphs. Easier said than done.

David

I personally think cool growers can go down to 35F......that include cool growing catt hybrids, australian native of various kinds, masdevallia's, Odont's, some paphs, Phrags, Dracula's and others I have forgotten. I grow all these outdoors down to 35F and they do fine.

So I think Cool is cooler than 50F.

That's just my opinion of course.

I will have to agree. In fact I have left many of my warm and intermediate growers out in temps mid to low 40F with no problems. Granted this was only for a few days in a row, but still even my vandas showed no problem signs. I just watch my watering, and if anything is in bud I bring it in. Lately we have had 40's at night and mid 80's during the day.

Well, I know Sharry Baby *can* go down pretty far, close to freezing, or maybe lower. :unsure:

(she's finally inside, have no fear! but only as of Saturday!)

Back again

I recently posted my first Phrag flower ( a Schrodereae). In the bckground of that picture you'll see the edge of a cluster of Onc sphacealatum (sp?). Amber, I got a plant of this about 6 years ago, broke it up and used some old stocking to mount them to some calistimon trees. The one in the picture is about 5 foot wide or 10 or so in circumference. It has 12 spikes on it up to 5 foot long. The calistimon it's on is right next to my driveway. Temps reached 43C last Summer (average of 35) and dropped to 4 in Winter. The plants is thriving and I believe the key here would be shade, air movement and regular watering. :)

Cheers
Stephan

hi stephan,
I also have a small calistemon tree in my garden but I wouldn't dream of mounting anything on it. doesn't it need to be watered once or more a day?
sometimes we have strong winds in the winter, and I'm afraid to loose an orchid for one day like that.
anyway, I traded most of my onc. hybrids and kept only the ones that are easy growing and a few I realy like.
the good news is, my Odontioda Violleta Von Holm, one of my fav is now spiking after 3 years I couldn't bloom her :D . I'm guessing it's because we have a true fall season this year unlike the previous years. I can't wait to put the photo here!