Gourds Birdhouse (Net Wt. 2g.) – Matures in 100 days. Birdhouse gourds (also know as dipper gourds) are easy to grow on fences or trellises and once dried they make ideal homes for many kinds of birds. To make a birdhouse, drill a hole 1 to 1 ˝ inches in diameter and a few tiny holes in the bottom for drainage. For longer lasting birdhouse varnish or shellac.