Cactus greenhouses in colder zones (6, 5, 4, etc)

Do-it-yourself projects such as greenhouse or shadehouse builds and related topics.
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Aloinopsis
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by Aloinopsis »

Oh, thank you. That's much less expensive than I expected.

Keeping things around 45 degrees is a challenge for me currently (giant, empty, room with windows facing south and west) because of the windows. I've considered covering them up because even with just 1-2 hours of direct sun per day it heats up quickly, but I can't bring myself to do that. I love the sunlight, especially when it's so scarce in winter! lol
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by Pereskiopsisdotcom »

Aloinopsis wrote: Wed Jan 09, 2019 4:40 pm I have actually had the EXACT same experiences and observations--that freestanding greenhouses basically don't happen in my area, or, when they do they're uninhabited for winter (i.e, they grow annuals, fruits, vegetables, etc only from early spring to late fall).

I do wonder about the attached sun rooms. At some point, wouldn't the size outweigh the practicality? I mean, most south-facing walls on a house have other things there (windows, heating units, driveways, etc) so even if you had a solid brick wall most homes would probably not be extremely conducive to that.

If I buy a home in the next few years I'm going to look for as much unobstructed southern or eastern wall space as I can find, though.

I've even thought about having a "room" inside a greenhouse where the most sensitive (to cold) plants could be kept, so basically a heated central "room" with the rest unheated. I don't know how practical that is (or isn't), though.

I've also seen wildly-varying estimates like you have. It makes sense, since structures are built, maintained, and heated differently. But the huge variation is what puts me off the most, because of the uncertainty.
South facing sun rooms can get unbelievably hot even during the winter in Canada. To the point that some cacti will get sun burned. That said, you are right, they are used by other family and have obstructions in the way. For mine, I build shelving units like bunk beds (the sun room is larger than a typical bedroom) by which the cacti are stored on 1020 trays. Like you, I'm in the territory of owning thousands of these things so it gets tricky with family, guests and pets. Fun to show off, but there's worry about damage, contamination, and all of that plant matter leads to higher humidity. That's mostly why I am moving away from using that room. But if you do buy a home it's a great starting point for having a nice collection.

PanaMark basically has the ideal set-up for our conditions. I would argue that's your best route, at least until you can get some predictable data on electricity and heating costs. That's where I'm heading. One of my target properties for development is actually an old garage which can easily be converted with the appropriate triple poly. All of my cacti will do fine for at least 6 months, a portion will be fine for 8 months. And they will all get a winter rest. The most sensitive and tropical varieties will likely be retained under grow lights. For those going into hibernation, dry conditions are paramount. You want the least opportunity for molds and fungus to develop. A lack of humidity will also discourage rodents and insects.
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Interests include: Rhipsalis, Turbinicarpus, Gymnocalycium, and Lophophora.
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Aloinopsis
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by Aloinopsis »

Just want to share this tiny update: https://www.buzzfeednews.com/article/cl ... imate-snow

Some parts of Minnesota are now colder than the North Pole and will remain so for days. I wonder what people with greenhouses are doing. I know there aren't many, but surely there must be a few. It's crazy to think about!
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7george
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by 7george »

Aloinopsis wrote: Fri Jan 11, 2019 2:48 pm Keeping things around 45 degrees is a challenge for me currently (giant, empty, room with windows facing south and west) because of the windows. I've considered covering them up because even with just 1-2 hours of direct sun per day it heats up quickly, but I can't bring myself to do that. I love the sunlight, especially when it's so scarce in winter! lol
I think that for most cacti there is no need to keep temperature so low constantly. Most of mine get minimums between 6 and 14 degr. C and maximums with 5 or more degrees higher being situated along windows of the house. I don't water adult cacti long months and this keep them dormant. I know would be a challenge with bigger collection taking the whole room. If you have plenty of sunshine think about getting cacti out of dormancy starting from February. In many habitats there are maybe just two cold months (December & January for northern hemisphere) and then cacti wake up.
If your cacti mess in your job just forget about the job.
°C = (°F - 32)/1.8
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Aloinopsis
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by Aloinopsis »

This is true. Many Mammillarias (for example) begin blooming at the end of the Chihuahuan winter, which is in February. Here are some of my modest little Mammillarias currently blooming. None has been watered since the first of October.

Edit: well never mind. It says my images are too big but they actually aren't. I don't know how to fix that.
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fanaticactus
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by fanaticactus »

Hi, Aloinopsis. I saw your post and questions and thought I'd share my experience. In retirement, I moved to very northwestern Vermont in the Champlain Islands. We have kind of a micro-climate here, being in the valley and not the mountains. Our zone is definitely 4, but some people claim it is such a high 4 it's almost 5. However, the topography creates breezy-to-very-windy conditions much of the year. Winters can be fairly mild to downright brutal. This was a bad one...snow- and cold-wise but not excessively windy, and my greenhouse did a great job of protecting those cacti that need 40 degrees for several months. I even kept some pots of orchid cacti (Epiphyllums) there for the first time, and they did fine. As for heat, I use a medium sized Vornado heater, which has been incredibly reliable for probably 5 winters. I have a remote digital thermometer in there, and the lowest the temperature got was 28...but just for one night (Feb. 1) and it didn't cause any harm. (I neglected to turn up the heater that night.) The only problem is that there can be a very wide temperature differential between night and day, when the sun's energy can warm it up inside to near 100! Now that milder weather has arrived, I have activated a large exhaust fan at the peak of the roof that keeps it in the mid-80s. The greenhouse is not shaded by trees, so I had to invest in various types of shade cloth to reduce the enormous heat that builds up during the summer. However, I take most of my cacti outside in the summer to enjoy the fresh air and to avoid getting baked under the polycarbonate panels. I only leave the rain-sensitive ones inside when there's rain predicted, and I use a cheap oscillating fan to move the air across the plants as well as the big exhaust fan.

This was a custom greenhouse made to my specs by a small company about 90 minutes south of here that builds only greenhouses. It has a poured cement floor with a drain. The two roof vents and the front window that faces south open and close using temperature-sensitive openers. I only wish the side panels were removable to allow air to circulate freely inside, but that would have made it more expensive than I could afford and would probably have compromised its ability to withstand winter cold and wind. The cacti that need to be kept warmer (50 or higher) during winter I bring indoors to my two unheated sunrooms, where they do fine. I've attached photos to give you an idea of the setup. It's in total disarray now after the winter and looks awful, so please excuse. If you have any specific questions beyond what I've mentioned here, don't hesitate to ask. Good luck with your cacti!
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Catch a falling star--but don't try it with a cactus!
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Aloinopsis
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by Aloinopsis »

Thank you. This information and these pictures are extremely relevant and helpful!
fanaticactus
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by fanaticactus »

Aloinopsis wrote: Thu Apr 04, 2019 7:27 pm Thank you. This information and these pictures are extremely relevant and helpful!
Good...glad I saw your post. I hope there's some information you can use, or at least modify to your own needs.
Catch a falling star--but don't try it with a cactus!
Hallow
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by Hallow »

I live in zone 4 from my experience moisture, not cold is the biggest killer of cactus in winter. For example, mid Winter thaw's if grown outdoors. If you keep them dry I am sure you would have success. For example, I had 2 beeked yuccas. They were in my unheated garage all winter with temps below 0. They did fine all winter long. Until I put them outside in March thinking it's warming up an they'll be fine. But soon they died because it was both cold and wet. I live in Wisconsin, we have cold wet springs.
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Re: Cactus greenhouses in colder zones (6, 5, 4, etc)

Post by Hallow »

I live in zone 4 from my experience moisture, not cold is the biggest killer of cactus in winter. For example, mid Winter thaw's if grown outdoors. If you keep them dry I am sure you would have success. For example, I had 2 beeked yuccas. They were in my unheated garage all winter with temps below 0. They did fine all winter long. Until I put them outside in March thinking it's warming up an they'll be fine. But soon they died because it was both cold and wet. I live in Wisconsin, we have cold wet springs. If you had a greenhouse catus type of green house here, I could see it working. Bet you could make some good money too if you sold some 😉
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