About This Project

A cold frame is a bottomless box with a skyward-facing window. Like a miniature greenhouse, a cold frame lengthens the gardening season by protecting plants and seeds from the moderately cold temperatures and drying winds of late fall and early spring. With the addition of a simple heater, a cold frame can be used nearly year-round to grow cool-season flowers and vegetables, and to give summer plants an early start.

The low-cost, easy-to-build cold frame presented here takes one or two weekends to build and uses widely available materials. You can place it on a deck or patio to grow plants in pots, or you can place it over a garden bed.