Cymbidiums will tolerate temperatures down to 0C without a problem though you might lose buds if they are subject to frost. This happened to some commercial growers when there was an an usually low temp in the western parts of Sydney, Australia. I think temps fell to -4/5C.

I'm not a Cymbidium grower, but they are everywhere here, mostly as pot plants in gardens, average winter temps in the eastern parts of Sydney in winter 7 to 17C.

You need a heater to get you through winter and the temps to aim at in your glasshouse are best given by growers with similar climates to the UK.

Temperatures info. from "Orchids for Everyone" an excellent book for orchid growers in the UK. Maybe reissued under another name.

"Mature plants should have a night temperature of about 10C during Auttumn, Winter and Spring."

"During severe weather when the outside temperatures drop below freezing, the indoor temperatures may be allowed to fall to 7C without harming the plants. The night temperature should not be allowed to rise above 14C. while the plants have flower spikes, as this can cause bud drop...."

"in the winter, a daytime temperature of around 15 to 18C is adequate. Often the problem throughout the rest of the year is to keep the temperature below 29.5C ......."

Cannot agree with that last sentence re. maximum temperatures because summer night temps below about 20C are critical for many types, but having observed all those clear glass "Glasshouses" in the UK, you have to wonder what the temps soar to when the sun shines in summer. There are many days here in summer where the outside temps gets above 30C. but the plants being under shade-cloth rather than in a glasshouse take the daytime heat in their stride. On those days you see the Cymbidium experts hosing around the plants to simulate the afternoon tropical downpour so that the plants will be cooled for the coming night.

Though you can grow them as garden plants without a lot of effort here....much skill is required to produce results like this and it is an impossible dream for many growers to win Champion Cymbidium at a major show. The competition is hot.

Cymbidiums at a small orchid society show.
{{gwi:140922}}

Thank you, Arthur I'll wait and see without too much optimism!

Richard, I live near Bristol (UK) so my conditions are not much different to yours. I have about a dozen cyms that overwinter in variuos places depending on their condition.

If they are in flower they are in the house. If they are in bud they are are kept in a frost free greenhouse (min approx 4C) If they have flowered or are showing no sign of producing buds then they are in an unheated greenhouse. Even with the prolonged cold spell we have just had they all appear to be fine.

From about April to Oct (when no danger of frost) they are outside but undercover so that I can control water and to a certain extent pests.

Terry, mine comes under the heading "showing no sign of producing buds".....so I feel a bit more confident that they are still healthy, the plant certainly looks OK.

thank you for the description of your growing regime, Richard

Hello Richard, I live in the West Midlands and due to lack of space in the house I left some old cymbidiums in an unheated greenhouse over this winter. A couple of them had spikes forming. The temperature dropped to -4 last week with no ill effects but when the temperature dropped to -8 I'm afraid the pseudobulbs went soft,leaves blackened and they are totally dead. So I don't think it's wise to go below freezing but they are hardier than you might think. I can't believe I was so thoughtless as I'm treating all my other types of orchids with kid gloves in the house.
Arthur your orchids are just stunning thank you for sharing.
Hazel.

Hazel, your post makes me feel even better - as mine only dropped to -1c...and nothing blackened or wilting.

Arthur, sorry! I forgot to comment on your picture - it's the first time I've seen so many different flower types.

--- and if that's a small orchid show, what's a big one like!?!

richard

Hello Richard, One of my most amazing memories was a visit to the world orchid show held in Glasgow over ten years ago. It was so beautiful I just stood and cried. It was the first time the show which is held only every two years had been to europe and was an absolute credit to the organisers and exhibitors. If you google it you will see they have just issued stamps to commemorate the event. I can't even begin to describe it. It was held two years later in Brazil (which of course I didn't visit!!)
Hazel.

Ummmmmmm.. for a few minutes after reading the above posts I got excited thinking I could get a cymbidium because it would tolerate 0 degree temperatures... then I sadly realized you were talking about temperatures IN CELCIUS. DOH So, they won't tolerate below freezing temperatures. Boooo. hahaha.

Mean while here in Florida United States they tolerate our wicked heat in high humidity and high heat..sometimes 100 degrees...hmmmmm with 100 % humidity

Arthurm, that is quite a photo!
My conditions could not be more different, however, my cymbidiums stay outdoors 365. Usually in the yard, but if the temperatures drop much below 18F/-8C I put them under the patio cover, which probably stays 5 degrees warmer.
Buds can tolerate temperatures well into the low 20sF/-5C or so without damage - much below that, the outermost ones start to get frostbite.
The problem here, of course, is providing enough chilling for most to bloom.
My growing tips: grow potbound in pure, fresh horse manure. Run water through this mix daily for the first month or so to leach out the salts.
Even the standards thrive, in full sun, foliage-wise, in our buoyant heat and humidity during the 10 months of summer. Getting flowers is another story.
Cheers - Nancy

100F and 100% humidity? hmmm, maybe in Texas. There are heaps of warmth tolerant Cymbidiums that will flower even though summer night Temperatures are mostly above that mythical 20C (about 68F). Some nice ones in a thread over on the orchid gallery.

The Standards are more of a problem. Here at latitude 33S is about the Northern Limit of where they flower well. They are better further south where the summer night temperatures are cooler.

Thanks - so at least the UK temperate climate does have advantages

There are some orchid societies in Australia that are just for Cymbidiums. Maybe some in other countries where the climate makes for easy growing.

Here is a photo of a competitive display put on by the Cymbidium Club of Australia. They set a high standard in the quality and presentation of the orchids shown.

Here is a link that might be useful: {{gwi:140921}}

wow, arthur, those a amazing pictures. years ago, we considered moving to Australia.. wish we had..
sue