I changed residences a couple of years ago and built a new greenhouse in doing so. My new greenhouse is a Harbor Freight 10X12 ft. model which is significantly larger than the previous greenhouse I was using which was a Kensington 8X12 ft. The 8X12 allows for 96 square feet of growing space while the 10X12 allows for 120 square feet; Furthermore the Harbor Freight greenhouse is nearly four feet taller than the Kensington. I should stress that size isn't everything, especially because the Harbor Freight greenhouse is of significantly lower quality.
Cons of the Harbor Freight greenhouse:
- Light and flimsy aluminum construction
- Easily removable panels (they can blow out in strong winds)
- The doors are easily jammed by dirt and debris
- Simple design and construction (only two kinds of pieces, metal and polycarbonate)
- Very reasonable price for its size (I got it on sale for $700)
- More easily modified. It is extremely easy to replace panels or install fans/vents.
It has been a couple of years since my greenhouse was built, and there are some signs of stress and aging. A couple of storms caused some serious damage, and as a result many of the aluminum pieces are slightly torn and my roof is crooked. I was surprised at how well the polycarbonate has fared, especially with the very hot conditions, none of them are cracked or torn yet. I regret not making improvements to the structural stability of the greenhouse originally, but I do plan on reinforcing the frame eventually. I bought and installed additional clips to more securely hold in the polycarbonate panels, as well as sealed some of the gaps with silicone. These minor improvements greatly reduce the frequency of displaced panels and helps seal the greenhouse.
One must choose a greenhouse suitable for their location and climate. For example, light aluminum framed greenhouses like mine should not be built in areas of high or moderate wind. Large greenhouses with weak frames should never be built in areas expecting a lot of snow; it is a common occurrence for snow to cave in the roofs of such greenhouses. Additionally, keep in mind that larger greenhouses are not only harder to heat in the winter, they are harder to keep cool in the summer.
My budget didn't allow for anything else but this greenhouse did meet my growing needs. I urge all serious gardeners/greenhouse growers to opt for a higher quality greenhouse or perhaps even a custom built greenhouse. Most importantly I advise potential buyers to do research and discover which greenhouse is best for their area and budget.
For help with greenhouse assembly and temperature control refer to my How to: assemble a greenhouse kit article.
This is an old picture of my greenhouse's position in my backyard. Due to space restrictions I was forced to erect it between two trees, and thankfully it has a wall to act as a wind breaker.
The peak of my roof is roughly eleven feet high, allowing for the cultivation of larger tropical plants and trees. In the picture is a papaya at about seven feet tall, with plenty of room to grow.