I left last season’s bumper crop of birdhouse gourds out in the field to cure. Periodically, I ventured into the cold to turn each one, affording them equal exposure to the elements and the sun. With every freeze and thaw, more of their outer skins sloughed away.
As they naturally dried, they also became much more lightweight.
Before I knew it, they were ready to bring inside for their next transformation. In just a few steps, some of these gourds would be ready to house area birds. Whether you’ve grown your own supply or you get gourds from another grower, you can follow these instructions to turn a birdhouse gourd into a proper birdhouse.
The Right Gourd for a Birdhouse
The typical birdhouse (or bottle) gourd has a small top chamber and a larger bottom chamber. These two chambers are joined together by a narrow “neck.” For best results, you should choose a birdhouse gourd with a bottom chamber that’s at least 8 to 10 inches wide. (This is the section of your gourd that will accommodate nesting birds and their young.)
Your gourd should also be completely dried and cured. In other words? Its water content has had time to evaporate completely. The gourd’s outer layers of skin also should have fallen away to reveal its hard, inner shell.
If your gourd still has some of its exterior layers, you’ll need to remove these and carefully clean your gourd. Although Mother Nature did most of my cleaning work for me, I lightly scrubbed the surface of the gourd with dampened steel wool. (See image Step 1 in the image below.)
This removes any residual flaky patches and can help to even out very dark spots.
In my case, I happen to like a natural-looking birdhouse—dark splotches and all. But you can lighten surface stains by sanding them with fine-grit sandpaper. Laying your gourd out in bright sunlight will also serve to sun-bleach its exterior.
The Hole Story
In part, the size of the entrance hole in your gourd birdhouse dictates which types of cavity-nesting birds come calling. Hoping to attract black-capped chickadees, I used a 1 1/4-inch drill bit. (Many wrens also like this size.)
Want to attract purple martins or swallows? They prefer larger entryways. You’ll want to use a 2-inch bit for martins and a 1 1/2-inch bit for swallows.
Before I drilled the entrance hole, I held my gourd up by its stem to see how it wants to hang. I noticed that one side of the gourd’s lower cavity naturally faced up and forward. Working with the gourd’s tendency to hang this way, I chose this side to locate the entrance. You’ll want to drill your own entrance slightly above the center line on one side of your birdhouse gourd’s lower chamber. (See image Step 2, above.)
At this point, it’s simple to remove the seeds and remaining debris from inside the gourd. However, this is optional. I chose to remove this stuff, because I’ll be planting the saved seeds. (See image Step 3.)
It’s worth noting that most birds are perfectly willing to do this clean-up on their own.
For Steps 4 and 5, you’ll need a 1/8-inch drill bit. First, with the entrance hole facing you, note the location of the sides of the birdhouse. On both the left and right side, measure at least 1 inch below the top of the gourd. Drill one hole on the left side and another on the right. (See image Step 4.)
Along the bottom of the gourd, drill a series of three to five drainage holes. (See image Step 5.)
Next, straighten out an old coat hanger and snip a couple of inches of excess off of both ends. Then, feed the wire into one of the two holes that you drilled into the gourd’s top chamber. Continue pushing the wire so that it passes through the gourd and out of opposite hole. (See image Steps 6 and 7.)
Taking care not to break or crack the top of the gourd in the process, bend the wire ends together so that they form a hook or loop.
To help protect it, I chose to seal my birdhouse with clear acrylic spray. (See image Step 8.) You may want choose to prime and paint your gourd birdhouse instead—particularly if you intend to attract purple martins. (Purple martins seem to like clusters of cavity nests that are painted white.)
If you intend to house chickadees, hang your gourd birdhouse in a wooded area near a clearing. For martins and swallows, place birdhouses high up in the open.