Attract Purple Martins with Gourd Birdhouses
Here is a fun habitat project for those who have already made traditional nesting boxes and are looking for a challenge.
People have been making gourd birdhouses to attract purple martins for a long time. According to eNature.com, "the custom of erecting a martin house to attract these beneficial birds was practiced by the early settlers, and by the southern Indian tribes, who hung clusters of hollow gourds in trees near their gardens." These birds eat lots of mosquitoes.
Gourd birdhouses are best for only one species, the purple martin. Other birds may try to nest in them, but it's not really safe.
"As houses for birds other than martins, they cannot be adequately predator-proofed," says NWF Naturalist Craig Tufts. "They work best swinging from a short piece of cable for martins and most other birds don't like or won't use a house that moves."
Do Purple Martins Live Near Me?
Before you make a gourd birdhouse, you need to know if purple martins live in your area. This bird lives mostly along the east and west coasts of North America, breeding in Canada. These birds can be hard to spot except near gourd colonies. The male bird is navy blue and black in color. The female bird is pale gray.
Where Should I Put Them?
You'll need a lot of space to make your gourd colony. You need to string up at least 10 of them in any area because they like to live in groups. You'll also need a pole that is very high up.
The gourds can be challenging to grow. They need a long growing season. The best areas to grow these gourds are in the southern United States. However, if you live in the north, it just takes a bit more discipline.
"Gardeners as far north as Maine can grow them if they really know how to head-start plants, " says Tufts.
If you head-start your gourds, you need to start them four weeks before the last frost, and then put them in the garden in late spring in well-prepared fertile soil. Select a sunny, well-drained site because the seeds will rot in cold, wet soil. Make sure your transplants are at least two feet apart.
"When your gourd plants start to vine, keep them well fertilized with regular compost top-dressing and you'll have a bumper crop," says backyard expert Cathy Nordstrom.
The type of gourds that you need are from the lagenaria group, which includes a type of gourd called Birdhouse.
According to the Ohio State University Extension, "these plants produce white blossoms that bloom at night. Lagenaria gourds are green on the vine, turning brown or tan, with thick, hard shells when dry. Gourds are ready for harvest when the stems dry and turn brown. It is best to harvest gourds before frost."
Making a Gourd Birdhouse
- Pick a gourd that is at least 10 inches wide.
- Clean the gourds with soap and water or warm vinegar water.
- Apply rubbing alcohol to the surface.
- Dry the outside of the gourd. Put the gourds in a dry place and let them sit for at least four weeks. Check them often and take out any that start to rot.
- Dry the inside of the gourd. This can take a few months. According to the Ohio State University Extension, "Providing warmth during the internal curing process will accelerate drying and discourage decay. Adequate curing is achieved when the gourd becomes light in weight and the seeds can be heard rattling inside."
- Cut a hole with an expansion bit or a key hole saw. Make sure the hole is towards the top to keep the babies from falling out. For a Purple Martin, the hole needs to be about 2 ½ inches wide.
- Cut small holes in the bottom. According to the American Gourd Society, "A few holes drilled in the bottom of the gourd will provide drainage and help keep the gourd dry. Drill a hole through the top and place a thong or wire for hanging." Don't attach a perch below the hole because this gives predators something to hold.
- Ideally, don't paint the gourd, but a layer of varnish or shellac will increase its strength.
- Hang the gourd houses at least two stories up. Make a cross bar on a pole and hang multiple gourds together from a strong cable wire. According to the American Gourd Society, "Keep martin houses away from leafy areas and buildings and where there are no overhead wires. The idea is to keep the flight path open. Hang your gourd houses with the opening away from prevailing winds."
- Take pictures and submit them to our Wildlife Gardens Flickr group!