Start with a leg up

On a level surface, lay out two seven-foot 2x4s on edge to start the first leg module (illustration at right, top). Trim three 2x4s to 27-3/8 inches for one leg brace and two shelf supports.

Attach the leg brace flush to the bottom of the legs, using two 16d nails or two 3-1/2-inch deck screws per joint. Attach the shelf supports 16 and 32 inches from the top of the legs. Repeat these steps for constructing the second potting center leg module.

Raise the roof