Even the sturdiest of the species -- any species -- can appreciate a dry, warm, quiet place that offers refuge in the teeth of a raging storm. The ubiquitous butterfly is no exception. Although not a necessity for survival of the species, a simple, well-placed, backyard butterfly box can shelter butterflies who may over-winter in temperate climates. A coat of paint and an attractive design can add all-season structural interest to your garden, as well. Building a butterfly box is so simple, because it has only a single purpose: to shelter butterflies in hibernation. They won't eat or cocoon or emerge from larval state in your box -- they'll stop, sleep and slip away. So all you'll need to construct is a four-sided box, with a roof, roof block and box bottom. Two pieces of lumber and some finishing nails will do the job nicely. Use a piece of bark as an inside perch.
To help guide your garden project, you might want to make a rough sketch of your butterfly box first. Imagine you're viewing your finished box from the side -- a narrow structure about 20 inches tall in the back, about 18 inches tall in the front, and about five and one-half inches wide. You'll want to give your butterfly box a roof that slants forward from back to front on an incline of about two inches, to allow your box to easily shed rain, snow and tree debris. A block of wood nailed to and slightly smaller than the underside of the roof, will keep your roof securely in place.
To make sure your butterflies can get into your shelter should they need it, you'll chisel four or five entry slits into the front panel. These will be vertical cuts no wider than one-half inch, and no longer than three or four inches. These little access windows will not only allow the butterflies in and out, but also will keep the predatory mice, voles and birds out. Now that you have a rough idea of what shape your finished butterfly box will take, you can prepare your materials. For lumber, you'll need:
* one board: one inch thick, five feet (60 inches) long and eight inches wide. From this board, you'll cut both side panels of your butterfly box, as well as the box back.
* one board: one inch thick, three feet (36 inches) long and 10 inches wide. From this shorter, wider board, you'll cut out the front of the box, the roof and the floor.
Begin by measuring, marking and cutting three 20-inch panels from the longer piece of lumber. Lay out two of the three boards vertically. Using a ruler and pencil, measure and mark your diagonal trim depth of about two inches down from the panel top on the right-hand side of both pieces. Draw a diagonal line from the upper left-hand corner down to meet your marks, and trim both pieces.
When you're finished, each panel's left side should be 20 inches high and its right side should be about 18 inches high. Lay out your third 20-inch panel, vertically. Measure and mark the board to a width of about 5 1/2 inches, and trim the piece. Use finishing nails to assemble both side panels to the outside of the back panel, making sure the tallest edge of each side panel is where you attach it to the back of your butterfly box. Before you trim and secure the box front, roof and bottom, be sure to nail -- rough-side-out -- one or more small pieces of tree bark to the sides or corners of your butterfly box. This little bit of "furniture" provides a home-away-from-home perch for any butterflies who take refuge inside.
Trimming the front panel, roof and floor
Before you trim your second board to make the front panel and remaining parts, stand your box up and measure the width and height of the front opening, to be sure to cut your front piece fairly closely. The opening should be about 5 1/2 inches wide. Using your pencil and measuring tape, measure down 18 inches from the top, mark the spot and draw a line straight across the 10-inch board, and cut the board into two pieces. Both pieces should measure 10 inches wide and 18 inches long.
Lay out one piece vertically, and measure across its width, to 5 1/2 inches. Mark that measurement at the top and at least three other places along the board. Then draw a straight line down, connecting the marks. Trim on your marks to produce a new board that's going to be 18 inches long and 5 1/2 inches wide. This will be your front panel. Set it aside.
Finishing the roof
Lay out, vertically, your second 10-inch by 18-inch piece. Measure down 9 1/2 inches from the top, mark at left, in the middle and at right, then trim the piece across on your marks. On the side of the board that measures 10 inches, measure across to seven inches, and mark. Trim the wood on your mark, to produce the box roof with dimensions of seven inches by 9 1/2 inches. Set this aside.
Making the roof block and the floor
You'll have a piece of lumber remaining that is now 8 1/2 inches wide and 10 inches long. Take three inches off its width, to produce a board that is 5 1/2 inches wide and 10 inches long. Lay that out in front of you vertically. Measure and mark down from the top to 5 3/4 inches. Draw a line across and trim. You now will have you butterfly box bottom, which is the piece of wood measuring 5 1/2 inches by 5 3/4 inches, and the roof block that you will secure to the underside of the roof. The roof block should measure 5 1/2 inches by 4 1/4 inches. Secure the bottom to the box using finishing nails.
Assemble the roof. With both pieces laid out vertically, lay your roof block on top of the larger roof piece, leaving a two-inch space at the front and a two-inch space at the back, and centering the roof block at the sides. Secure with finishing nails. Before you finish assembling and painting your butterfly box, pencil in the access slots on the front panel. Use a drill and chisel to remove the wood from the slots. Slip the front panel in between the two sides that are already in place.
Cap the box with its roof, and you're ready to decorate. Use bright colors -- reds and oranges and blues and yellows, to catch the eyes of the butterflies and to fit in with its surroundings. You can mount it on a post in the middle of a garden plot, or secure it to a tree. Don't be disappointed if your butterfly box isn't a hot spot of comings and goings. Free little creatures that they are, butterflies may not choose to frequent your butterfly box for winter hibernation, but you can still be sure it will grab lots of attention all summer long.
