Growing birdhouse gourds is an easy, inexpensive way for you to create housing for your feathered friends. Lagenaria siceraria are a species of hard-shell gourd with distinctive elongated necks and broad, pot-bellied bases. Each gourd seed that you plant is capable of producing more than a dozen gourds in varying sizes. The gourds grow on a green-leafed vine that can reach lengths in excess of 20 feet with proper care, according to Sally Roth, author of "Attracting Birds to Your Backyard."
Soak your birdhouse gourd seeds in a bowl of warm water three to four days before planting day to speed germination. Leave them in the water overnight, and then place them in a plastic sandwich bag with a damp paper towel until you are ready to plant.
Choose a sunny, well-draining area of your garden or backyard to plant your birdhouse gourds. Prepare the soil by first tilling it with a hoe. Add about 2 inches of compost on top of the soil, and mix it in thoroughly.
Gather the dirt with your hoe into gently mounded hills that are about 2 feet in diameter and approximately 6 feet apart. You'll be planting six to eight seeds per hill, so make as many hills as you'll need to use up all your seeds.
Plant the birdhouse gourd seeds in the hills at a depth that is approximately two times the length of the seeds. The Purple Martin Conservation Association suggests that you put as many as eight seeds in each hill to compensate for poor germination. Place the seeds at least 3 inches away from each other in each hill.
Wait for the seeds to germinate. Water the seeds with your garden hose regularly to keep the hills moist. When the seedlings are about 2 inches tall, thin each hill to two plants.
Erect a trellis for vine support when the main vines reach about 12 inches. According to Roth, this practice helps keep your gourds from growing twisted or bent necks.
Watch for white, night-blooming flowers to appear on the birdhouse gourd lateral (side) vines. Some of these blooms are male, and some are female; look for small gourds to appear below the female flowers. Once your plants have developed an adequate supply of gourds, start pinching off any new flowers that form; according to Roth, this allows your plants to put more energy into growing and ripening the gourds that are already on the vine.
Harvest the gourds in the fall after a solid frost. The vine should be dried and brown before you remove the gourds.