A flower box filled with colorful tall and trailing annuals, biennials, perennials, or a blend of all, is a welcome sight for everyone. Not only is it an inexpensive way to dress up bare walls, but it adds warmth and color to a particular spot and enhances its appeal. Flower boxes are typically hung outside windows to decorate the exterior of a house and bring the aroma of flowers inside on a windy day. Although this task may seem daunting to some, it really is not the case.
Measure the width of the window and purchase a flower box that is up to 8 inches longer so it overhangs the brackets on each side by several inches.
Move to one side of the window and measure an inch downward, just below the windowsill for sliding or double hung windows, and mark the spot with a pencil. This spot determines the location of the top of the bracket. However, measure 6 inches down if your windows swing outward when open.
Repeat the procedure on the other side of the window. Step back to review the spots so they are both at the same level, otherwise the brackets will be tilted and your flower box will not be hung straight. Make necessary adjustments by relocating the second spot so it corresponds with the first and is directly parallel to it.
Move to one side of the window and hold a bracket so its top is over the pencil mark. Drill a pilot hole into the bracket for the top screw with a countersink drill bit. Insert a 3-inch galvanized decking screw through the pilot hole so it holds the bracket to the wall. If attaching the bracket to an aluminum or vinyl surface, drill a pilot hole through the siding as well.
Hold a carpenter's level against the bracket to make sure it is level and straight before drilling a pilot hole for the second screw. Drill this hole above the horizontal leg so it is hidden under the flower box. Insert a 3-inch screw through the hole. Your first bracket is installed.
Move to the other side of the window and hold the top of the second bracket over the mark. Use a carpenter's level to make sure it is level and straight. Repeat the procedure to attach it firmly to the wall.
Lower the flower box over both the brackets. Step back to check how much overhangs from each bracket and adjust it so it is exactly in the center and the overhang is equal.
Drill a pilot hole into the back of the flower box to attach it to the bracket. Insert a 2 1/2-inch decking screw into each hole so the flower box is secure. Fill it with soil and flowers.