You don't have to have a country cottage to enjoy window boxes. Use decorative elements in your planting boxes to create a style that matches your home's exterior architecture. If you have a modern structure, choose a solid color paint that matches the trim of your home. If you have a rustic structure, use a complementary wood stain. Of course, if you have taken the country or whimsical approach to your garden, use stencils or hand-painted designs on the outside. Window boxes require minimal carpentry skills and a few tools and supplies.
Measure the window where the box will be placed. You may make your window box whatever length you like, but creating one that is the same length as the window is aesthetically pleasing.
Cut two wood boards for the length of your window box. The height of your box will depend on the lumber you choose, an 8- to 12-inch board width is a good choice. Cut two wood boards for the width (or sides) of your box.
Create a frame shape with the four boards. Place the two smaller boards to the inside of the longer front and back boards.
Screw four galvanized screws into each end of the longer boards (and down into the sides of the shorter boards). Use your drill and screwdriver attachment.
Use your tape measure to precisely measure the outside length and width of the wood window-box frame.
Cut a piece of plywood to the wood frame measurements.
Put the plywood on top of the wood frame (the top and bottom should be identical). Use galvanized screws and your drill to attach the two pieces together, frame and plywood. First, use a screw at each corner of the plywood and down into the wood frame. Fill in with additional screws every 4 or 5 inches all the way around the plywood.
Drill holes through the plywood at random. This will allow the excess water from the plants to easily drain through, keeping the plant roots healthy.
Turn the window box over. Attach an eye hook at each top end of the back board of the box. Attach additional eye hooks across the back board, about every 6 inches. The number you need will depend on the length of your window box.
Attach curved metal hooks outside, under the window. Make sure they match the spacing on your window box. This is where you will attach the eye hooks on your box.
Sand any rough spots on the window box. Use paint or wood stain to seal the box.