I'm not a newbie to gardening or seed starting, but with major garden expansion plans this year, a "cold frame" is looking like its going to be a necessity, and that I am totally new to.
My issue is I will be starting a lot more plants this year, particularly peppers and tomatoes, and I'm positive I'm not going to have enough area with my grow light setup to keep all my plants there until they are ready to go in the ground. So correct me if I'm wrong, but this tells me my best solution is either to purchase more light setups, or build a greenhouse/coldframe. I know that the two are different, but sort of have the same idea. This is where my questions and concerns come in.
I may have jumped the gun a little, but I already took some salt treated lumber laying around and built my frame. It is basically a wedge, but with a slightly raised front. So the front, or what will be the southern most side is 6" tall. The back wall or northernmost side, is 42" tall. The width, or east/west measurement is 4', and the depth, or north/south measurement is 3'. Not sure if i've confused everyone already, hopefully not.
-The back wall that is 42" tall will be plywood that is nailed and glued to ensure it is sealed as best as possible. I will paint the inside of this wall white to help reflect the light onto the plants. So far so good?
-The same with the side walls or wedge shaped pieces. Plywood nailed and glued. Inside painted white. Still good?
-Now the top is where I start to have questions. Before i started this i looked around for cheap or free windows and found nothing. I have a bunch of clear plastic around. And I am more than willing to go purchase plexiglass, or polycarbonate, or whatever I need. What is the best material to use here as far as material, thickness etc? And while I'm here, does anyone know the approximate cost of the material I will need? Anyway, other than one brace in the center, I will make this whole south facing roof/side out of this clear material. Obviously, it will be a little tough to build it to have a really good seal, yet still make it accessible daily for watering/maintenance etc. Anyone have pics/ideas on how to actually construct this part to maximize my efficiency?
-My other questions have to do with scheduling, temps and such. First, what kind of daytime/nighttime temps do I need to ensure I can keep my plants in this thing and ensure they don't die? I'm thinking I will have to move my first batch of plants to this thing when they are about a month old...is this too soon as far as plant size?
-I'm sure i've overwhelmed you guys with questions, so my last question for now is about using an actual heater in this thing. I have several small ceramic electric heaters at my disposal. Would it be a good or bad thing if I set on up inside my coldframe on a timer? I'm thinking maybe set it to turn on at say 10pm for 30 min, and 2a.m. for 30 min to try to ensure I keep heat in it. Is this at all necessary?
I'm sorry for asking all of this guys. I really am. Any help that anyone can offer is greatly appreciated! Thank You.