Acquiring a greenhouse is a big step as a gardener which allows you to both harden things off a lot easier and to extend your season.
I want to start by chatting about the particular greenhouse we use on the acreage. It’s a polycarbonate structure and I’ll tell you the story behind it, what I use it for, and my thoughts on whether we’ll invest in a new greenhouse this gardening season.
We were extremely fortunate to acquire our polycarbonate greenhouse from our former neighbour. They had moved into the house next door and I had asked if they weren’t gardeners if they would consider selling it to us. They obviously thought about my offer. When we moved away. they offered us the greenhouse for free as long as we would move it ourselves because they wanted the space for a hot tub!
The greenhouse didn’t come with very much shelving, so I just took some plastic garage-type shelves and moved them in there. They’re not quite as efficient as the Costco wire shelves, however, the Costco wire shelves are too tall, so I can’t fit them into the space.
We don’t grow any plants in our greenhouse year-round. For me, the greenhouse serves as the second phase in my hardening-off process.
When I first start hardening off plants, they initially go on my deck. That way, if the weather changes quickly and I need to bring them inside, it’s very easy to do so. Once they’ve passed life on the deck with flying colours, I will move them to the greenhouse, with frost fabric at the ready and a space heater just in case the temperature drops too low.
I typically only use my space heater in my greenhouse in April, and I only use it if the overnight temperature is going to be lower than -2 to -5 Celcius. It just depends on what I have out there and how much frost tolerance each of those plants has. For a more detailed explanation, you’ll definitely want to purchase The Frost Proof Flower Garden because I have temperature guidelines for every single plant so you’ll know what kind of temperatures your plants can withstand.
Finally, the plants move to stage three and move to my raised beds where they can get a little more used to the wind (pictured below). After that, they’re finally planted.
Related: Growing with an Unheated Greenhouse in Zone 3
I don’t have any sort of ventilation in my greenhouse, so I often leave the door open to provide as much ventilation as I can. The previous owners had the greenhouse hooked up to electricity, but we unfortunately don’t over here. You can always purchase a simple fan, cut out a hole at one side of the greenhouse, and put the fan up for additional ventilation. Some greenhouses also come with vents in them. So if you’re not particularly handy, even though greenhouse kits are expensive, I would say they’re worth it just to have the ventilation and other features planned ahead of time.
Unfortunately, I don’t know a lot about passive solar greenhouses, but if you live in a cold climate similar to mine in Zone 3, I suggest that you follow the Arkopia YouTube channel. Dean and Jess have a beautiful passive solar greenhouse set up. It’s absolutely huge, and something I dream of having one day. In the meantime, I definitely want to use some of their tricks, like keeping water jugs in my greenhouse.
Another idea I’ve had is taking some of the chicken bedding with manure in it, putting it in Rubbermaid tubs, and putting that in my greenhouse to see if that makes a difference. These are just some of the things I want to try, so definitely be watching my Instagram in March and April to see if those things work or not.
Once the gardening season is over, our greenhouse serves as sort of a storage facility. We use our greenhouse to store any of the supplies we need for weddings or other gardening supplies that need a home, and then in the fall, all of the pumpkins will sit there to cure as I don’t like to leave my pumpkins outside for the chickens to ruin them. On rainy days, it’s also a lovely place to make bouquets if the weather doesn’t cooperate when I need to be arranging!
We also have a high tunnel, which we could easily close off the doors and convert into a greenhouse. However, I really like the polycarbonate, and, if we could afford it, I’d want to build the type of greenhouse where we would be growing food directly in the soil or creating raised beds to grow in.
I don’t know if I’d ever have the budget to create something like they have at the Arkopia Farm, but if I could take some of those principles and apply them on a smaller scale, I definitely would. I like the idea of being able to grow in the greenhouse and being in the greenhouse for as many months out of the year as possible.
Best Flowers & Vegetables to Grow in your Zone 3 Greenhouse
I like to start my sunflowers, zinnias, pumpkins, and cucumbers in my greenhouse. Even though these can be direct sown, I feel like I have to seed start most things I grow on the acreage because of my hydrophobic soil–it just doesn’t hold moisture well enough to do it any other way.
It can be confusing when you start using a greenhouse because people think you can move all your seed starting out there, but that’s not entirely true unless you have some sort of overnight system of heating it. Think of your greenhouse more as a place to harden things off. And if you’re going to start anything in your greenhouse, it will probably be in the beginning of May, like those three weeks before your last frost date, and it will be very weather dependent.
Answering Your Questions About Greenhouse Growing
What kinds of greenhouses are available?
For home gardening, there are several types of greenhouses to choose from. The simplest option is a pop-up greenhouse, which consists of metal tubing and poly fabric. These can be easily set up on your deck or any wind-protected area, making them perfect for hardening off plants over six weeks, after which you can conveniently take them down.
Another option is similar to a high-tunnel greenhouse but with closed-off ends, providing a more permanent structure. Finally, there are traditional greenhouses like the one in front of my raised beds, which can be built using different materials – either glass, stapled-on plastic, or corrugated polycarbonate sheets.
When is the best time to purchase greenhouse building materials?
A good time to purchase greenhouse building materials would be sometime in January or February because then you have enough time for them to arrive if you’re trying to start things with the gardening season. However, the best time would be to buy the materials in the fall. If you build it in the fall, then it’s ready to go that spring. That being said, whenever you’re able to build one is when you’re able to build one!
Are the hard-sided metal kits you find on Amazon (4×6 or 6×6) worth it for the $200-$300?
I can’t really speak to this, as I’ve never ordered or tried one. My guess is it would be sort of like the chicken coops that you get off of Amazon where it’s fine in other places where it’s warmer and maybe not as windy. On the prairies, my guess is that they won’t hold up quite as well as you need them to. I think, if you’re handy enough and you have the option available to you, it would be better to build something.
How to choose the location of your greenhouse?
You want some place that gets full sun. Our greenhouse is actually tucked by a tree, and I’m ok with this. In the early spring and winter, there are no leaves on this tree so it really doesn’t interfere with the sun. By the time there are leaves on the tree it shades out the greenhouse enough so that it’s still really hot in there, but I think it helps it from becoming super dangerously hot. If it’s an option, I would have the greenhouse protected from the wind as well, especially if you use poly fabric that can rip with really fierce winds.
How to choose the right size of greenhouse?
The right size greenhouse is the biggest greenhouse you can afford.
Even if you first build it and think “Wow, this is way too much space!” you’ll be surprised how quickly you’ll fill every inch. Before you start building, make sure to check your local bylaws around greenhouse building. If you live in the city, you might need to keep it under a certain size to avoid getting a building permit. Living in the country, you usually have more freedom, but it’s still smart to check if there are any rules. If not, build whatever you can afford!
How do you keep your greenhouse from blowing away in prairie winds?
For our high tunnel, Michael pounded rebar pretty far into the soil. If you watch this video on YouTube, he explains it better than I can. This is how our high tunnel doesn’t blow away. We also built both our high tunnel and greenhouse in fairly protected areas, so far it’s been enough that nothing has blown away.
I think this will be our fourth year of having our high tunnel and it’s survived all the winters and the snow load. I think this is our third year with our greenhouse, and it’s still going strong. So the tree protection is definitely the way to do it!
Related: How to Build a High Tunnel in a Northern Climate
What’s the difference between a greenhouse and a cold frame?
A cold frame is basically just a mini greenhouse. They essentially function the same way, especially if you don’t have any heating capabilities.
Can you fit out your greenhouse (after spring) with screens to create a summer house?
I don’t see why not! Especially if you’re building your own greenhouse with glass windows or something like that, I’m sure there is a system you could make to replace some of those windows with screens with no problem. I think this is a great idea!
What’s better: double or single-walled?
I have never had the luxury of having a double-walled greenhouse, so I guess I don’t actually know for sure if a double-walled or single-walled is better. But from what I understand about the principles of keeping things heated, I think a double-walled would be better because it would keep the heat in for longer.
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Happy gardening!
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