Windsor Flower Box Planters These elegant window, porch and patio planter boxes are made of durable maintenance-free PVC plastic. They are far lighter than wood with an extra-deep design and internal Water-Minder insert to promote healthy plant growth. The natural white PVC material will not turn yellow, fade or flake. Can even be painted with any exterior paint to match home decor. Includes brackets for easy mounting. 48 long x 9 wide x 10-1/2 high.