Cobbling Together an Inexpensive 'Greenhouse'

Let's get one thing clear: I have greenhouse envy. Big Time. 

 Image by BC Greenhouse Builders LTD

Image by BC Greenhouse Builders LTD

Come on, who wouldn't want THAT? Oh yes, and I'll take the estate to go with it, thank you very much.

Considering that Tom is in public education and I'm now a student, I'd say our chances of ever having a greenhouse like this one are nil. I suppose it's ok, because then I'd have to have the lifestyle to go along with it - the clothes, the hair, the nails. And, well, clearly none of that's for me. I'll take my 1000 square foot 1949 redwood-sided ranch house any day, and prefer to stay in my comfortable flannel and jeans, and continue to chew up my cuticles. 

So that means I need to cobble something together to use for seed starting. Probably not for tomatoes and peppers - they'll need the lamp and heat pad inside for the first couple of months at least - but other seeds. In fact, the way I'm doing things, planting directly in my bed with seed, is really wasting time. If I have a place to get seedlings going, it would really ramp up my efficiency. I would be able to germinate seeds in a warm, controlled environment, and transplant often for a continual crop through the season. 

Tom and I did some framing when we built the chicken coop, and it was an interesting and fulfilling project, but I don't really have a place for any kind of permanent structure. Plus, I want to try it out first, so something that I throw together with mostly found materials would be ideal. I've been thinking about it for quite some time and I may have a solution.

Back in 2013, my dad and I built a frame for Adam's 5th grade graduation, a sort of portal for the kids to walk through as they entered the theater two by two (the theme was traveling through time and space - so it had a clock I painted at the top). It's been in my garden ever since, mostly just sitting there, too pretty to throw out (and made of redwood!), but not a whole lot of use. I once grew runner beans up it. Tom put hanging brackets on it for potted plants. But this week I've been looking at our garden with new eyes, and when I saw this frame, I thought, what if I moved that to a South-facing wall and used it as some sort of greenhouse? So today I moved it.

That was the easy part. Now I've got to figure out how to make it useful. My plan is to take off the clock and the plant hangers, insert brackets for shelving, cut some light wood for the shelves (maybe three? four?) and then encase the whole thing in clear 6 mil plastic poly, and then I'll be in business. During the winter, this tower would get sun a large part of the day (when it's not raining, of course) and in the summer, it would get only morning sun - so the location is perfect. With a flap in the middle of the front for access and ventilation, I think it could really work. I have a rain barrel nearby as a water source, as well. 

So here's my question for you: Have any of you built something like this? Or have any experience with greenhouses? Or might you have any ideas about how to put this together? I'd like as much input as possible.