As I packed plants into my basement this fall I started to think about how to make a greenhouse work on our 0.3 acre lot. I considered a lot of options but ended up getting the 16′ X 12′ Garden Grower Package from Greenhouse Megastore. To avoid more complicated permits, and to fit in my yard, I kept it under 200 sqft. The Greenhouse Megastore sales rep said I should have 4′ spacing on the supports due to the wind load in my area. After putting up the building and making it through one thunderstorm that knocked down dozens of trees in my neighborhood with no damage, I am confident 4′ spacing is overkill. Ultimately the soundness of the structure was one of main reasons I went with the Garden Grower though and I am happy to have a strong structure.
I applied for my permit at the beginning of the year and got it quickly. Next I ordered the Garden Grower package. All this went smoothly and it took about 2 months (as they said it would) to ship. While waiting I worked on the base for the greenhouse. I decided not to pour concrete and used 6X6 pressure treated timbers instead. So far they seem to have worked out well. The foundation is set on a bed of compressed stone and is three timbers high everywhere except the door, which I lowered to one timber. The extra 18″ is a big help inside and makes for a very spacious feeling greenhouse.
For extra security, though probably unnecessary, I secured the base with eight earth anchors that each hold over 1000 lbs.
Delivery was more complicated than expected when the freight company called me and said they could not deliver to my address. I have had plenty of large items delivered on similar size trucks, so I don’t think it would have been a problem, but ended up renting a U-Haul and meeting the driver in a nearby parking lot, loading the greenhouse kit into the U-Haul, and then unloading it at my house.
Thankfully we had pretty cooperative spring weather, though getting parts was made more complicated by business closures and efforts to quarantine.
The kit takes a lot of work to put up, but I did all of it except the covering by myself. For the covering my daughter helped hold pieces straight while I attached them. The instructions leave a lot to be desired for someone who doesn’t build greenhouses for a living, but the combination of instructions and the video that is provided made it reasonably easy to figure out.
I added a second door to comply with the Japanese Beetle Harmonization guidelines that allow me to ship to the lower 48 states. I also added screening over the intakes as well as outlets. The outlets were probably not required since they only open when the fans are blowing, but better safe than sorry.
The shelves are waterproofed using pond liner material so that I can water from the bottom by flooding the shelf. This has worked well for me and greatly reduces watering time and mess.
Of course no good project is ever done. I am currently finishing the shelves inside the greenhouse with lights for the lower shelves. Automatic watering/fertilization and a more advanced control system for it all are all still in the works.
Finally, a couple of aerial views from my drone. The greenhouse is inside my fruit cage. The net goes up on the fruit cage mid June as the blueberries start to ripen. The fruit cage is great for ripening figs and other fruit without interference from squirrels, which seem to number in the 100s on my block.