I just couldn’t resist buying several greenhouse kits the other day. They were on a discount table at our local auto store (I love that store) for $25/each. It got me thinking about how to use them and what I’d like in a small greenhouse. So here’s my thinking.
As a heads up on these kinds of kits, they’re not going to be as good as a real backyard greenhouse and serious gardeners may want to think about which will be more useful to them.
They were only a few dollars and I could use them until the plastic disintegrated with no problem. (This turned out to be about 3 years) I thought I could then recover them with my own plastic. (Turned out to be easier said than done to get a good fit) And if not, I could use them for other things. (Yes, I do) More later on this but generally, the frame became a cold frame when laid on its side and the shelves were repurposed into useful coffee tables for the dock.
Construction ease
Some kits can be a bit on the complicated side; the unit I purchased came with a single sheet of instructions (exploded view) and was a bit of a challenge to figure out but not one that was overly difficult if you sorted all the parts beforehand.
First bit of advice – do sort all the parts and fittings beforehand so you don’t have to figure out if you have enough of those 38cm parts versus the 42cm parts. 🙂
This kit was screw-free. No fittings to tighten or mess up – nothing to drill. It was simply fit the pipe lengths into the plastic corners and push until tight.
Construction durability
Greenhouse kits are going to come in various levels of durability. Let’s be honest here, the unit shown in the pictures isn’t going to be all that durable. It’s light steel tubing with plastic joints, no foundation, no attachments to the ground and a plastic covering that’s not replaceable. One wind storm (if it were out in the open) and this one is well-wrapped around a tree.
But it suits my purpose perfectly. It’s out of the wind, well-sheltered by the house and garage and I’ll put a cement block or two on the bottom pipes in the spring when I have it covered.
If you want a more permanent greenhouse, I’d suggest you look at one with foundations and how you’re going to secure it from the wind.
Covering
The unit pictured has a heavy plastic covering that we’ll use first thing in the spring as a frost protector – remove it after all danger of frost and store it carefully for the summer. Because it’s in the shade, it will not be exposed to UV rays that degrade it and I expect to get at least 5 years (as I said above, I got three) from it before I have to make my own covering.
Expose this plastic to the sunlight for one summer and that’s the life expectancy.
UV-treated plastics will last 4-5 years when exposed during the summer.
If you want something more permanent, you’re going to have to look at fibreglass, poly-carbonates of one form or other or glass.
Intended Use of Greenhouse Kits
We use ours as a seed starting frost protection system. That’s it. We’ll toss the seeds in there in the spring and free up some windowsill space. The racks give us all the space we need for medium cold-hardy plants. Perennial seeds can be right outside and tender vegetable crops can either be started in this unit later in the season or given premium space on the windowsills or (hopefully) the indoor growing area under lights (planned for the basement).
If you’re looking for more than a seed starting or frost protection system, then you’re going to have to evaluate some of the other issues I’ve written about – with heating, ventilation etc.
Portability
This is an excellent system if you don’t own your own house and tend to move regularly. The system pulls apart (remember no screws to rust) and stores in a box about 3 feet long by 2-inches high and 8-inches wide.
Update: June 2021.
Those small kits lasted a few years and when the plastic cracked it turned into a major hassle to recover them. I gave up. I now grow my plants using lights in the basement and harden them off before planting.
