I'm desperate to get a jump on spring, and was thinking of starting seeds in a coldframe. Flower seeds, some perenials, some annuals. Is it too early yet? We're looking at some coldish nights this week, just about freezing, but no actual freezing yet.

Daytime temps are expected between 49 and 68 for the next week. Night time temps between 34 and 46. What temps will the frame be needed to be on?

I was thinking of making the coldframe out of pvc tubing for the frame and clear plastic from a farm supply store (like the kind you would use for a paint drop sheet). Anything else cheap that might be used to insulate on a really cold night?