Hi
Hope you get some good answers .lol Mine began as an attached screenroom and over the years turned into a shadehouse and in 2000 my first attempt to turn it into a green house. The really tough question is what to cover it with. Have used lexan, shadecloth,shadescreen. removeable shutters and vine overgrowth. For heat sources , electric, oil.My last attempt was to heat 3 pools of water which runs down a waterfall inside. I used standard aquarium heaters in 3 location totaling 1200 watts. This last cold spell was the first real test. It allowed the water to drop to 53 and the air to 45. Went back to using open lattice only on the roof and hardware cloth only on the walls.. Any wall covering I've used as either held too much heat was a maintenence problem or both. My shadehouse also houses a large aquarium and some tropical birds both of which should not be exposed to less than 60.. The aquarium was insulated and birds brought into the house. Birds in Aviary were left to the infrared heater ,which they ignored lol.
I would LOVE to turn this into a real GH. Any ideas .?? More watts?? gary

Hi D'Ann,

Just wanted to share with you that in the last 16 years I've been growing orchids in Sarasota, I've never lost one to cold. I used to have a greenhouse, but now I have a 'lanai house' with screen on all sides, and a polygal roof. There is a tall wall about 7 or 8 feet from the north side of the house, but none of the sides are enclosed with anything. I have no heater. The phals (I have maybe a dozen), and vandas (of which I only have a couple), are the most cold-sensitive, so I put them on the north side of the house, for protection from the wall (which acts as somewhat of a wind-break). It got down to about 32 or 33 here, and about 40 on the night before and after, and I've had no damage whatsoever to my orchids. They all stayed in the lanai house these nights, and even the phals, which are all in spike, look fine. I make sure not to water them during cold weather, for fear some water could be left in the crown of the phals and cause rot.

It looks like you're in zone 10 as well. How cold did it get in your area? You may be surprised that these plants are tougher than you think, and as long as they are not completely exposed to the weather (some kind of a roof, or against a wall, etc.), they will do just fine as long as they don't stay cold and wet.

Anna

Anna
Thanks for the info. My experience has been generally like yours. This debate is raging once again on the GH forum. The jist there is that orchids should never be exposed to less than 40 lol. I can't argue if it's good for them but I know they can survive down into the 30's lol If I had to choose a number I'd say 30. obviously freezing will cause tissue breakdown even temperatess will not tolerate that.
I really don't think I need temp controls for my orchids as I really don't think they would do better if not exposed to lows. Apparently you don't either??
The birds are a different matter lol. Again the wisdom
is that they can't tolerate below 60. I know better than that from my own observation.but never want to risk it. The fish is no problem just throw in a heater with some bubble wrap on top. Was hoping the escaping heat from the water would at least creayte pockets of warmth. Solve all the problems certainly wouldn't mind keeping the orchids above 50 as a bonus. I have grown orchids out on the trees for many years and like you I don't think I had a single loss from low temps!! Squirrels eating them was serious lol
So a quuestion is , if you could build an "ideal" structure
what temmps would you keep??
I'm going to refer to your pix of "stressed" orchids
as proof it doesn't matter lol. Your's seem fantastic!!! gary

Gary, I have to stress that my orchids were not totally exposed to the weather. This structure does have a roof, screen on the sides, and there is a nearby wall on the north side that acts as a good windbreak. All these help a lot, I'm sure. However, I think these things are all I need. In my old age, I have become a lot less obsessed about orchids, and if I would have lost a few, it would not have made me so sad as in the beginning. I have become more daring over the years, noticing that it didn't really matter if I left them outside with some protection. Personally, I think the catts bloom better with some cold stress.

By the way, Olya mentioned in another thread, that she had had some damage to her orchids. We should try to find out what her particular situation was. Perhaps it got colder, perhaps they were wet, perhaps they were completely exposed to the elements. I hope she checks in and tells us what happened and which ones suffered. It is good to compare.

Hi guys,

I think it matters how you grow them.
I like to expose my plants to liquid sunshine.

The only time I feel as though I need to cover / heat my orchids is when we have those rare nights when it is wet,
temperatures under 40 and there isn`t a cloud in the sky, and NO WIND.

Last year we had one of those nights........and we got patchy frost..........

Trouble is I go to bed and its windy , but when I wake up the wind has stopped and then I am in trouble.

And that's another problem I have . I don`t use aliflor or any other rock material because I don`t have the
wind breaks that you naturally have with building / houses in the city. Any plant I buy that in planted in rocks
seem to suffer root damage when blown over.

So , as you can see wind is my friend and my enemy.

I lean towards cattleyas , vandas. My Dad use to divide his cats when they got to big.
Maybe I should reconsider the specimen plant theory.

I really need to make up my mind soon... we will be building the two houses soon.

Our neighbors pine came down and took out our old orchid house........... So I have a new chance do
make changes. Hopefully it will be the last :)

D`Ann

Hey there
Yup, first time in about 7-8 years of growing orchids I have frost damage...Not much, but not pretty either

I have a shadehouse - 20 feet by 10 feet, and it stands in the open, so all orchids get lots of sunshine...The structure is covered with 50% white shade cloth. Certainly, having it next to trees and some structures would probably help, as they would stop a lot of the winds. Most of my frost damage to other plants usually occurs in that area, while same plants under the huge oak do fine.

For the winter, we covered it all with 6 mil plastic - bought it from International Greenhouse Megastore...It works fine when temps dip very low for an hour or so...But, unfortunately, the temps were below freezing for quite a few hours, and long exposure got them. The plants are alive, but in one particular part of the shadehouse - more exposed to the wind than the rest of it, is where all the damage occurred. Mostly young cattleya leaves. One phal (out of maybe 30-40), and a few warm growing species.
But, considering the temps we had, the damage is minimal.

I am now going to buy two heaters, small space heaters...Whenever it goes below freezing, I will be turning them on. Otherwise, having plastic has protected the plants all the way to mid 30s no problem.

The plastic will go off the structure late February. For now, it is good for peace of mind and is great for raising humidity during the winter months.

Olya

Hi
Olya I'll bet your temps dropped below 32 .?? Big difference between a frost and freeze.
Must tell you a story about the time I used plastic as a wind block . I covered the outside and was feeling smug the next morning when it was 55 in the shadehouse. 33 out side. Went to work before daylight came home at 5 temps
were in the 60's. Inside the shadehouse the temps were 140
due to the solar warming !! Only things I lost were those in the shadehouse!!
If your going to cover the shadehouse I'd suggest frostcloth or canvas. If that sun is beating down you'll still get heating but not nearly as bad as transparent plastic. My last attemp at exterior covering was partial with frostcloth . The main problem with that has been storage. One giant piece of cloth If you use it be sure to roll it up don't fold!! come that cold day you unfold it will fall apart. This can also be left in place with simple venting for the next night. Plastic will have to be removed and replaced depending on daytime highs. A lot of work!!
As for me I'm going to remian wide open. I found some tables for calculating heat loss from water so should give
me a better idea of wattage needed.
This system also has the added advantage of evaporative cooling in the summer .So far have not had to wear a jacket lol I'm also using this system as a semi,hydroponic setup
I want to turn the shadehouse into sort of rainforest with all plants in fixed positions . Sort of an overgrown terrarium.lol
BTW See no damage to any of my orchids ,I brought some indooors to a 60 degree heated hoom the shadehouse which I know fell to under 50 much colder in spots. Those on the trees were covered while some were left uncovered.. So far see no difference. I registered 35 in the yard. so no frost.
Good luck with whatever you decide!! gary

Gary, whatever you are making sounds very interesting
As far as the cold, the temps definitely dropped below 32...
I keep the plastic on, but do open the doors for air circulation...so far, the temps did not rise too much, even with high temps we had before the freeze. Will definitely take the plastic off late February

Olya
Be sure to keep an eye on the max temps. Solar heating is incredible. Of corse if it's overcast or remains cool
different story . I had the problem of going to work before dawn and returning after dark. Right at dawn is always the coldest and fronts usually last 3 days.
Has anyone seen pix of the "Conservatory " that Donald Trump built?? 30 foot vaukted ceilings with polarized glass, refrigerated humidity controlled interior
I saw some limited pix in a real estate mag mostly centered on the house . Amazing what you can do with only 31 million lol gary

Thanks for the advice, Gary :) Overheating is something that does concern me :/ - need a better solution than plastic, looks like it