I really do not know what zone 3 four season greenhouse would look or feel like. Most large glasshouses in cooler climates are copying Tropical Lowland Climates. There was one in Wales UK that copied the the climate in California, South Africa and Southern Australia and grew the native flora from those places. A nice change from the usual.

Orchids! Tropical Lowland, Tropical Savannah, Mist Forest. etc. You cannot grow them all in the one set of conditions!

Hopefully, some of the real orchid growers in Northern USA and Canada will add to this.

Thanks for the reply! I may not have been clear - I’m aiming to build a subtropical greenhouse IN a zone 3 climate!

As for the conditions, yes - well aware of the wide range of habitats from which orchids originate ;-) I have no interest in growing South American cloud forest species, or Mediterranean terrestrials.

I mainly grow East African and Madagascan Angraecum/Aerangis species, primarily “intermediate-warm” growing which is the vague orchid lingo we use for the temperature range described above.

I’m less in need of orchid cultural info, more in need of greenhouse engineering help and how to create the conditions described above

Thanks again!

EDIT: I realize my original post may have been cross-posted into the orchid and northern gardening forumS when houzz asked me to choose ‘tags’. I’m new to this format (I’m used to the old gardenweb days) so apologies if my comment doesn’t make sense

This is a big challenge with a big bank roll, due to all the requirements. The best advice will come from someone who built one and is currently growing orchids in your zone. I am z 10b. It can be done. The price tag could be astronomical. I am known to take on challenges but the best advice and most economical on a relative basis will come from someone in zone 3.

From a layout consideration I would enjoy the space for relaxation or entertaining. I would plan enough space to include a small table and some chairs. And maybe a chais lounge. It could be the best hang out of the property. Breakfast and the morning paper? A glass of wine and some music. I would prefer same as floor level as the house. with a masonry drained floor. Off the kitchen if possible. Then keep a bench of fresh herbs too. Maintaining comfort for orchids in z3 will attract humans. A very desirable destination to your property.

@shavedmonkey (Harvey in South Fl.)Z10b totally!! that’s the dream. I’m thinking hammock.

What you propose - (a ground level structure) would be a very reasonable alternative. I’m apprehensive, but prepared, for the potential costs (to a degree - never done this before). I recognize the luxury and excess this represents, and I’m not proud of this....Thankfully in my industry, part of moving to this zone 3 horticultural wasteland were the economic means to make this possible.

People here have 4 season indoor heated pools. I’m telling myself this is the same on a smaller scale...maybe that’s just false self reassurance though!

Ground level attached to common living space is the spot. Due to the expense, failure and redo is not an option. Therefor a successful, experienced architect and or engineer with satisfied customers you can visit and interview. With good research this will be money well spent. It must be right the first time!

I don’t have a greenhouse, yet anyway. It is something I have always wanted and have spent a lot of time thinking about how I would do it. I also work in construction, not residential but a lot of things carry over so here are my thoughts.

I don’t know if you have checked with contractors for pricing yet but my first thought was that the framing of the garage was not intend to support that type of load so you will have to beef up the framing of the garage first which will add cost. I would imagine your garage is not heated so you will also have a hard time controlling the temperature. It will get hot on a sunny day but very cold at night.

I do have a sun room on the south end of my house off of the living room. It’s just a narrow room with windows on 3 sides and I put 2 levels of glass shelves across the windows. This is where I keep my plants over winter. I like it because being attached to the main house it’s easy to access, and if I move it’s just another room in the house. The plants in the room take care of the humidity but I only shoot for 60% and everything seems fine. The down side is that it has wood floors so I have to be careful about spills and it’s kind of small.

Ideally I would build a solarium type of structure off of my kitchen. I would build it partially in the ground to help control the temperature. I would put a cistern in under the floor and collect rain water. I would also have a back up heat source for power outages. The walls and floors would be stone and the windows and roof glass and aluminum. It would also need a door to the outside so I wouldn’t need to carry stuff through the house.

From November thru February your sun angle is so low and the days so short that the need for supplemental lighting would negate the value of it being a greenhouse during that time...maybe even longer.

tj

I agree with Tsuga. Your lighting will be a problem.

I grew Angraecums and Aerangis when we lived in NY, zone 5.

I also had a sunroom attached to our kitchen which was on the second floor. Our house was built on the side of a hill and the back side of the house was raised 25 ft, thus a raised kitchen and sunroom. The sunroom did not have heat. Many times I would leave the kitchen door open to let heat in but couldn't do that in the dead of winter.

I put all my orchids outdoors in early spring throughout the summer. Brought them in in September or when the nights started dropping into the 40's. I moved all into the house and put them under lights. We had floor to ceiling windows in our living/dinning room which faced S.W.

Winter days are dreary, cloudy and grey. Not a lot of sun nor light. Phals did fine there but everything else needed supplemental lighting. Even then, the lights I used were not enough for certain species.

I think your biggest problem growing the orchids you want will need supplemental lighting. If you heat the greenhouse you need to provide humidity. If you can attach it to the house, it would save a lot of work. Near the kitchen, even better!

I was able to bloom my Angraecum/Aerangis every year.

Jane

@jane__ny hi Jane - nice to see you kicking around here a decade or so later. I used to go by calvin_orchidlover and used to be more active here.

Will definitely explore artificial lighting. I currently grow 100% under lights so it hopefukly won’t be too big of a transition. I was pleasantly surprised moving to the prairies by the amount of winter sun, albeit shorter days. Winter days are bright cold and crisp, compared to the grey skies of the East.

I was actually hoping elevating the greenhouse to the second floor would help with the low sun angle problem by bringing it above obstructing features, but maybe that line of thinking doesn’t make sense?

The low sun angle means the light is passing through more atmosphere. The light at noon on 12-21 is less intense than at noon on 6-21.

Are there any local commercial year-round greenhouses you could get tips from?

tj

Good idea - I think I'll get in touch with the university greenhouse program. They run a 4 season greenhouse year around. There's a 4 season vegetable production company in Osler SK that sells tomatoes lettuce and cucumbers year around so I'll contact them too

Ask the professor for a referral for an architect and/or engineer. To have a greenhouse at your latitude and temps -35, means to me a professional needs to be onboard. To build what you want at these extremes the cost is multiplied many fold. So it is logical and probably cost efficient for the right specs and design. Make an appointment with the professor involved to ask for a professional referral.

Calvin, Calvin, where have you been!!!

If I had known it was you.....

Welcome back!

Jane

Sounds like a walk in plant room might be the best solution? No special design needed. Just a worry about the amount of lighting needed. The setting of fans/ exhaust fans to come on when the humidity becomes excessive and the temperature controls to maintain the conditions needed for the type of orchid that you want to grow plus plumbing to get rid of excess water.

I'm sitting in the fish tank room. It contains the 600 litre fish tank and two Phalaenopsis. Not a big room but the evaporation from that tropical fish tank has never caused a problem in this room and in the rest of the house.

Currently conditions in this room 4.33 pm are Temp 17.6C humidity 43%. Here is latitude 33 almost 34 South.

Outside at the nearest AWS Temp. 15.9 humidity 19% sun is shining, a wonderful day if you can get out of the arid wind. That is why those two caspar milk toast Phalaenopsis are next to me in this room. The fish tank has been here for about 20 years, left by my son when he left home. No green stuff on the walls etc.

Other orchids are outside braving the elements in two glasshouses and a shade house.

Would be nice to get to them on a rainy day without trekking down the yard!

Anyway, I'm not offering a solution, but perhaps "glass" is more of hindrance than a solution at latitude near the poles.

Thanks for the input all - I've contacted the university greenhouses. I have also toyed with the idea of a plant room with lots of windows as @arthurm2015 mentioned, and may have to get a room like that too. I'm being very greedy and indulgent, but this is *it* in terms of near-foreseeable-future residence. As such, I'm giving in to years gardening desires that have been suppressed by, what has been up till now, a nomadic life. The collection has traveled a cumulative 8881km/5518 miles over the last 10 years, which has been a nightmare!

@jane__ny thank you for the welcome back : ) been busy getting a few degrees, but still growing orchids, still pushing trying to push the limits with light...burnt a bunch of stuff real bad when I moved back out here to the prairies, but new leaves will grow, right?

I also remember you by that name. Welcome back and Jane I hope you have been safe these days)

The praries? Any pics of your area and of the area where you are thinking of putting that greenhouse)?? Sounds like a nice area and that is one big dream too.

Mike

https://northernhomestead.com/greenhouse-for-winter-growing/

https://www.ecowatch.com/couple-builds-greenhouse-around-home-to-grow-food-and-keep-warm-1882128131.html

I reversed their idea and built a greenhouse inside my garage.

This is a Palram Glory greenhouse with twin wall polycarbonate panels. Spectrum king Low Pro Flower on light rail And various fixed LED. As a starting point I would talk to Palram's local distributor and see what R value you would need and what you can expect in your zone.

https://youtu.be/_pmxK9hvzAI

I like your ideas but it is very hard to conceptualize.

I'm in 6b

I am in zone 5b ( Southern Ontario) I build a small greenhouse to get me up to zone 10A. Yes it could be done like you said attached will be the only way I think in your case. Giving a minimal height will save you on cost too. As far as vents yes there are automatic ones that can open once it hits 85F. Someone mentioned a sunroom. That might actually be what you need.

The temps you are looking for are not realistic for a greenhouse. An enclosed sunroom with actual roof could do that. In a greenhouse for even here in 5b Winter temps 11-17C/days,

winter nights 5-9C. Summer temp days 28-35C nights 18-22 C That's everyday with fan and door open.

some orchids can handle the cold and some can handle desert heat

Thanks for the input all - lots to think about. @Matt z5b - Greenhouse 10a thanks for sharing your experience!

Hi - I just saw your post while looking for greenhouse heaters and I thought I'd weigh in. I grow orchids in my greenhouse in the Detroit/Ann Arbor area. We are zone 6 something. When I got my greenhouse 15 years ago, I decided on a Florian. It has 2 panes of glass that are sealed with an air gap. My greenhouse is 11x18 on a city lot, attached to the short end to my detached garage.

I looked over your ideas, and you have some good ones, but I wonder if having orchids up on a second floor will work for you in the long run. You said it would be on top of your attached garage. Hmm. One of the big reasons I wanted a greenhouse is so I could water my plants quickly and easily. I have a floor of 8 inches of pea gravel with pavers on top. When I water it drains through the floor.

I was surprised at how energy efficient the Florian is, I was concerned about being able to maintain a temperature of 67 during the day and 55 at night. My husband doesn't gripe about it. I am using 2 Southern Burners, one is mostly a backup in case the weather gets super cold. The upsetting part about the burners is that they quit making them! It's very upsetting! Now I'm looking for an alternative that allows for a set-back thermostat. <sigh>.

Having your greenhouse attached to your house is a good idea. Your water could come from your house too. Mine goes through a trench to the greenhouse - so I have to have a water heater for winter.

It's easier to heat a greenhouse than it is to cool it. I had Florian put in 2 full length automantic roof vents and they are terrific. I also have two full-time fans mounted near the ceiling. I have some white shade cloth that I roll down in spring and up in fall. I have low E glass in the roof, but that I could do without.

I do have some condensation neat the ridge at the top of the greenhouse. My husband put in a gutter and that problem was solved. My heaters contribute to the humidity, since they are not vented. We had to cut a smallish hole in the garage because the greenhouse is so tight that the pilot lights were going out.

What else? Oh yeah. I was very careful to keep bugs out of my greenhouse and I was fairly successful for the first couple of years, but I found that in spring the scale and mealybugs are just awful. It helps to take them outside for summer, where you can spray them and keep them separated from your other plants.

I sure wish you a LOT of luck. I wish I had a greenhouse that size! I'd have such fun filling it up!

Denise aka Catasetumkid

Thanks for the great post, @Denise Nash. I also like the idea of being able to splash water around a bit without worrying about it. I’m thinking a good drain with a graded waterproofed floor, like what they have in shower rooms, and then some sort of cedar slats on top for the floor.

I think given what everyone is saying, I’m moving away from a greenhouse Idea and more towards a rooftop solarium, with lots of windows. That way I get some benefit of the insulation, while also getting sufficient light.

Thanks @Tom H! I think that makes a lot of sense, and the last thing I want is water damage. I think I always envisioned it as a giant shower room, and showers get fully drenched on the second floor all the time. But I have no engineering or building knowledge, so I believe you. I’ve advised our designer of this and to scratch the 2nd floor idea off the drawing board.

@Denise Nash - I got in touch with a Canadian grower in Edmonton (same zone3b/4, slightly northern latitude) who’s been running a greenhouse x 14 years. He also went with Florian and loves their product. He grows Dendrobium and cattleya with no supplemental light, but lives on an acreage with minimal shade. He uses some spray on stuff for shade each summer, but I like the idea of rollable shade cloth that you have.

Yes custom showers are done upstairs all the time, even though there is a high failure rate for the custom built ones because there is just a massive percentage of untrained installers who won't follow the national technical standards. Big wet floors are more challenging because of the transitions. Most tile showers have a curb to walk over you wouldn't want entering your greenhouse from the main home. No-curb showers are extremely difficult to do correctly, and combine that with putting a wood-frame pre-hung door right at the edge of what would be your no-curb shower. The pre-hung aspect makes tying into the sill nearly impossible without simply relying on caulk (which always fails eventually) up under the sill where the installer can't really see if he's doing a good job. Too many uncheckable high-skill variables, so the chance of failure is high.

Another aspect to consider if you attach it to the house, even at ground level, is moisture management. The high-moisture greenhouse requires a full vapor barrier (not just moisture barrier) to protect the house at any adjoining walls. but now one whole wall of the house can't shed interior vapor like usual. Modern cold-climate houses are not at all similar to the old English manor with the gorgeous attached greenhouse we've all seen. That old house lets the wind blow right thru it & never risks trapping moisture and causing mold in the wall cavity. Modern houses are built very tight, so make sure your architect and builder really understand their building science and can explain to you how different types of insulation effect the location of the dewpoint in a wall, and why there will be no chance of condensation of interior moisture in your wall cavity. This part is very doable though, and I would not hesitate to do it on my own house.

If you are going with roll up shade cloth, do it right. I have wingnuts to tie it down in summer, and I tie it up in winter. I recommend going with a light colored shade cloth, mine is a white/beige color. Aluminet is a good product, too. Remember it's easier to heat your greenhouse than it is to cool it, and you don't want to absorb heat by using dark colored shade cloth.

I live in zone 5, and have tossed around a million ideas for a heated space for my orchids. If I were to do a room, and was building new construction, I would go with geo thermal, just for the heating and cooling savings. In a nutshell, pipes are laid 6 feet under the earth, where the temp stays at a constant 55 degrees...then it's pumped into your home, so when you heat, you're staring at 55 degrees...to get to 75, now you only have to bring the temp up 20 more degrees...same with cooling in the summer..it's a lot cheaper when done with new construction, and the heat pump technology has come a long way. There might even be tax breaks, and grants ...I haven't looked in a while.

I haven't looked at the posts above. This is a link that someone put on my threat about a greenhouse in zone 5. There is a Youtube video too. Sounds interesting and uses geothermal.

https://greenhouseinthesnow.com/shop#8407fd7f-3be9-4d52-a8b0-c6c982ca8e4f

Four season in zone 3 is asking too much, unless you own a gas well.

There is a fair amount of literature on solar greenhouses, but for our climate none really work well.

* Single pane glass gives you R1. Twin wall polycarbonate is R2. You can get more layers up to 5 layers for R5.

* 16x24 has about 500 sq feet of roof area. If you settle for R2 covering, that 250 BTU/hour/F/ft2 to heat it. At -20 C = -4F you need 68- -4 = 72 degree differential * 500 = 36,000 BTU/hour to heat. That's a small hot water heater running continuously.

* You don't need that 24 hours a day. Only when the sun isn't on it. When the sun shines, you need 6 air changes per hour to keep up with the plants taking CO2 out of the air. (Figured on planting density of a commercial tomato greenhouse)

* During daylight sunlight is proving about 800 watts per square meter, figured at the cross section area. You will probably need to vent air for cooling even in winter. You want a heat exchanger to warm up exterior air that is too cold.

I've been experimenting about green houses and low hoop tunnels and all that.

I'm in zone 7a.in oklahoma. Right now I just got an 8X16X 8 cattle panel greenhouse.. I've used it for spring transplants of tomatoes , peppers ,ect. .Also got some superhot ( Carolina Reaper , ghost ,Dragon Breathe plants in containers. And just planted some greens in the raised bed in the GH.

'

Okla homa

Zone 7a has a different set of problems. Most years you don't have to heat it much to get through the entire winter. You do get the occasional Siberian Express which will mean you will need the capability of pouring a lot of heat into it now and then. Some kind of propane system?

If your coldest anticiapated temperatue is -30 F, you need to be able to raise the temp by 62 F to keep it above freezing, and with a lot of peppers and eggplants, they sulk for a long time after getting anywhere close to freezing.

Your biggest problem will be to keep the greenhouse cool in the summer. (This is a thread about 4 season greenhouses...) Lots of greenhouse operators shut down their greenhouses for the summer, or remove the plastic entirely. A typical greenhouse needs an air change every 60 to 90 seconds to keep the solar temperature rise below 10 F.