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How to make a garden shelf
Attach frame supports to the back of the frame.
Each tier of this shelf will be comprised of one frame. The front and back of the frame are formed by 96 in (2.4 m) 2x4 boards.
There are four supports for each frame, and each support consists of one 21 in (53 cm) 2x4. Measure and mark where your supports will go with a tape measure and pencil.