What is a birdhouse gourd?
A birdhouse gourd is a hard-shelled gourd, often a bottle gourd, that is dried, cleaned out and fitted with an entrance hole so that birds can nest inside. Gardeners grow them as vines, and the dried shell can last several seasons if kept dry and cared for. Because they are lightweight and easy to hang, gourds have a long history as bird housing.
Which birds use gourd birdhouses?
The bird most associated with gourds is the Purple Martin. In eastern North America, these swallows depend heavily on human-provided housing, and large gourds hung on racks or poles are a traditional choice.
Other cavity-nesting birds may also use gourds when the size and hole fit them, though success varies by region and gourd size. Possibilities include:
- Tree Swallows and bluebirds, with an entrance of about 1 1/2 inches.
- House Wrens and Carolina Wrens in smaller gourds.
- Chickadees and titmice, with a smaller hole.
Entrance size is the main tool for choosing who can enter. See our guide to bird house hole size by species for typical diameters. Purple Martin gourds are usually much larger than those for songbirds, and martin entrances are commonly around 2 inches or a little more.
Preparing a gourd
- Cure the gourd. Let it dry fully, which can take several months. A dry gourd feels light and the seeds rattle inside.
- Cut the hole. Choose a diameter for your target bird and cut it smoothly, away from the thinnest part of the shell.
- Clean it out. Remove seeds and pulp. Wear a dust mask, since mold on drying gourds can irritate the lungs.
- Add drainage. Drill a few small holes in the bottom so water cannot pool.
- Add ventilation. Small holes near the top can help keep the gourd from overheating.
- Seal it. Many people coat the exterior with a sealer or paint. For martins, white is often used because it reflects heat. Keep paint and sealer off the interior.
Hanging and placement
Hang gourds from a sturdy wire, cord or rack so they do not swing wildly. For martins, gourds are normally hung in open areas with a clear flight path. Songbird gourds are usually hung or mounted at heights suited to the species.
Avoid hanging gourds where cats or raccoons can easily reach them, and avoid full sun all day in hot places. A pole with a predator guard is a safer option than a tree branch.
Maintenance and cleaning
Natural gourds degrade with time and weather, and the interior can hold moisture. After the nesting season, remove old nests and let the gourd dry. Cleaning bird houses in general follows the same steps, but go gently with gourds and avoid soaking them. Replace a gourd that is cracked or soft.
Pros and limits of gourds
Gourds are inexpensive, light and look natural. They also have limits: they cannot be opened as easily for monitoring, they may crack, and they are less predictable for small songbirds than a well-designed wooden box. Plastic martin gourds offer easier cleaning for martin landlords. For bluebirds, a proper wooden box such as one from our bluebird nesting box plans is easier to monitor.
Frequently asked questions
What bird lives in a gourd? Purple Martins are the best known, though wrens, swallows and bluebirds may also nest in suitable gourds.
Where should you not put a bird house? Avoid spots exposed to predators, constant all-day heat, or heavy traffic and noise.
Do gourds need a perch? Generally no. Perches are not needed and may help predators.