The most basic elements for a greenhouse from my limited experience are the covering and the structure to hold the covering. Some plants can tolerate having a blanket right on top of them to keep in the warmth--it extends the growing season and could be called a greenhouse of sorts. If seed starting is in the plans, one needs also shelves, space and good full-spectrum light. The reason all of us longing for a greenhouse don't have one is: it's pretty challenging to put all these together without a major expense. You've seen the full-color pictures in the garden catalogs, and you've seen the price tags.
Not long ago I was visiting my friend Liza and her garden. Lady Luck was shining warmly on me that day. Have you noticed when you're around very bright people your own imaginations gets stirred? Well, that's what happened that day. We were talking about her tomato support structure and greenhouses and growing good food and eating it when suddenly I saw it.
My vertical garden could be fall-fitted with shelves between the upright 4 x 4's. I love 1/4" graph paper, and soon ideas took shape. I calculated the sun's angle up through the spring equinox to determine the spacing of the shelves. They were sized to hold old plant trays I had collected plus large rectangle plastic boxes saved from buying lettuces last winter. Perfect. And for materials, it turns out I had plenty of good-but-not-so-pretty 2 x 2's that wouldn't mind the muddy overflow from watering seedlings.
About six weeks ago my excitement around this creative "get to" pulled the project onto the Things I get to do today and the structure was built. Winter was not even close so there was no need for the covering. But the very next day, I pulled up my bean vines to let the ripe seed pods dry. As I stood up, there before me was a shelf in the hot sun. Immediate gratification!
|Fall-fitted and ready for a cover|
|Top shelf detail: 2x2's on 2x4's (studs).|
Very soon the covering will be sewn from a woven, light-allowing, tarp-like fabric designed for this purpose. I'm fortunate to have a 12' x 50' roll in my garage that I begged off my sister awhile back. The perpendicular "tent" design has zippers and vents and grommets and doodads and whohaws to please the fussiest of plants and gardeners. The only cost to me is for some studs and a couple of zippers. Between now and the future blog on this subject, you can figure out how those items work together.