It’s not the busiest season in the garden but at the job site, one garden business is so busy right now no one is allowed to take a day off until after Christmas.
Despite their name, BC Greenhouse Builders Ltd. in Langley B.C. is a small family-owned greenhouse construction business. Selling home and commercial greenhouses right across North America, the company is shipping a huge greenhouse to Saskatchewan the day I arrive for my tour in early October. In Calgary, Garden Retreat near Chinook Mall has their sample home-greenhouses on display and it’s a nice place to go and dream on a cold winter day.
Yes, it is the season for dreaming and gardeners everywhere are dreaming about plants they could have grown if only! If only it didn’t freeze outside in May. If only it didn’t hail in July. If only there was a bit more heat in September. A home greenhouse might erase a gardener’s worries.
Sadly, small home greenhouses can also be trouble. They can overheat if placed in a south-facing location with no overhead trees or shade cloth. With Calgary’s brilliant sun, greenhouse plants can otherwise go from perfect to scorched in just a few hours. A passive venting system or electric fan also helps remove hot air.
At SAIT, an in-house designed and built demonstration greenhouse uses the latest technology to cool the summer greenhouse and insulate it in the winter, The cost of this bubble insulating structure is hard to estimate because it is a prototype with several innovations, but it is at least double the cost of a regular greenhouse because it has two layers and a bubble generator system.
Typically the insulating value of any greenhouse is very low. It is possible to add a bit more insulation by using 5-wall polycarbonate plastic – a product suggested by Kyle Exner of BC Greenhouse Builders for cold climate growing. The old glass greenhouses of the Victorian era look romantic, and the twin-wall polycarbonate is more common, but the 5-wall system gives more R-value than either.
If frost is threatening, plants will be okay indoors but if there is a deep frost, most greenhouses need a heating system to keep plants happy. I found this out the hard way after my tomatoes froze in late May when temperatures dipped to minus 8 degrees outdoors.
So it isn’t the busiest season in the garden, but it is a time for research and planning and dreaming. Imagine what you would do with a home greenhouse of your own?