Cold Frame — Cedar

A 4'x2' cold frame built from untreated cedar with a hinged polycarbonate lid, angled from 12 inches at the back to 8 inches at the front for rain runoff and optimal sun capture at low winter angles. The polycarbonate panel is 4mm twin-wall — it insulates better than single-pane glass, will not shatter if a branch falls on it, and diffuses light so seedlings do not scorch on unexpectedly warm afternoons. The hinged lid props open with a notched arm at three positions for ventilation, because the most common cold frame mistake is cooking plants on a sunny 50-degree day when the interior hits 90 degrees. Cedar handles the constant ground contact and moisture without rotting for years, and the frame weighs enough to stay put in wind without anchoring. Extends your growing season 4 to 6 weeks on each end — start hardening off transplants in early March, keep salad greens producing into December.