The bluebird population has been shrinking in the last 40 years, but the brightly colored little songbirds are returning in record numbers, thanks in large part to backyard birdwatchers. If you want to attract bluebirds to your garden, a dried gourd makes a perfect house, and the unusual shapes of the gourds will add an interesting element to your garden. You can purchase gourds, or, if you have space in your garden, you can grow your own.
Choose the gourd carefully and measure to be sure it's the right size. The diameter should be large enough for the bluebirds to turn around easily. Look for a gourd 6 to 10 inches in diameter.
Soak the gourd in a bucket of hot soapy water for about 30 minutes. Remove the gourd from the water and rinse it in clear water. Remove any outer skin that might be peeling and scrub the gourd until the skin is smooth.
Cut an entry hole in the gourd with a dremel tool or a hole saw. The hole should be 1 1/4 to 1 1/2 inches in diameter. It should be placed in the upper part of the gourd so the bluebirds can jump down into the larger, round part, and so baby birds can't fall out of the house. Be sure the hole isn't tilted up, which would allow rainwater to enter the house.
Drill three or four small drainage holes in the bottom of the gourd and two or three holes near the top to provide air circulation. Add two more holes at the top for hanging.
Clean the inside of the gourd with a long-handled spoon. Make sure all seeds and pulp are removed. Rinse the gourd and make sure the drainage holes are clear of debris.
Allow the gourd to dry, then protect the outside with several coats of shellac or varnish. Let the shellac or varnish dry between each coat. Hang the bluebird house with a piece of wire.