Courtesy of Scott W., Growing Gardeners Calgary Urban Farms , Calgary AB
I am setting up a 50’x12′ hoop house this. I was going to order greenhouse poly from Johnny’s, but a few people have recommended using vapor barrier as it stands up to hail better, is cheaper, easier to work with and can be dealt with in sections. Apparently it also helps to not burn your plants as well. I have a fair bit of wind and lots of snow where I am, so they also suggested using an elongated “portable car shelter” instead of a hoop house because of the added strength.
The vapour barrier I would be using is heavy duty 6 mil, comes in 8′ sheets and is UV stabilized. I am growing in a yard that has tree and house shelter on two sides and, according to our average wind speed and directions, that would buffer the wind we get.
The cost of building a strong, wooden frame greenhouse and using this heavy duty vapour barrier is $350. If I anchor it down, attach the plastic to the frame and also bury the plastic around the outside I will be golden. I have several friends who have done this here and it works excellent. I will be holding it down with wiggle wire as I have heard that is the best and allows for some rolling up of the sides. The main thing that changed my mind to spending a fair bit of money on this was the look of it. This is going to be in one of my property owner’s yards. I have a great relationship with him (he is also a restaurant owner/chef so I sell to him), but I wanted to keep it that way by making sure the hoop house doesn’t have ugly vapor barrier writing all over it. The shape will be straight up walls for 5′ and then an arch. This has worked well for my friends and will give me some headroom to work. If I put cross beams I could even hang some pots in there and really maximize the space, but we’ll see how it goes. This is a learning experience, and it really isn’t going to cost that much for me to try it this way. If it goes well I can’t wait to spend like $3k and get a really nice professional greenhouse (they are so fancy!).