From Gardener's Supply (www.gardeners.com)

Watch: How to Use Raised Bed Corners

Raised Bed Corners: the Fast, Foolproof Way To Build a Raised Bed

The hardest part of building a raised bed is constructing corners that are square, strong and trim-looking. Our ingenious Raised Bed Corners are brackets that cut building time and result in a handsome, sturdy raised bed every time.