Hard-shelled birdhouse gourds (Lagenaria siceraria) grow on vines that may reach 30 feet or more in length. Also known as bottle gourds, dipper gourds or bowl gourds, the various other names depict the use the dried gourd fills. Birdhouse gourds need similar growing conditions to other members of the cucurbitae family. Although not particular about soil type, birdhouse gourds require ample water, warm temperatures and full sun.
Plant four to six birdhouse gourd seeds in hills if you have room to allow the vines to sprawl. The University of Florida recommends spacing the hills 9 feet apart in rows 9 feet apart. Some growers control the vines by picking up the stray vines and moving them to create wide leafy rows, while other growers allow the vines to ramble at will. Home gardeners should plant several vines to ensure pollination. Birdhouse gourds are monoecious, meaning that the flowers are distinctly male or female. One vine produces both sexes of flowers. Multiple vines assure better pollination and therefore more gourds per plant.
Tie birdhouse gourd vines to a sturdy trellis to keep them completely off the ground. Use a trellis if your garden space is limited. It creates a large, vertical space for the vines and takes up a minimum of soil space. Mature vines and gourds are heavy, so build a strong trellis. Tendrils grow from the leaf axils, but they may not support the weight of a mature vine. Support individual gourds with extra ties on a trellis, so the weight doesn't break the vines. Growing birdhouse gourds on a trellis keeps them clean. The weight of a gourd hanging on a trellis pulls the neck straight, which may be desirable depending on the planned use for the gourd.
Birdhouse gourd plants require plenty of moisture. Vines fastened to a trellis dry out more quickly than those on the ground. Keep the soil consistently moist.
Allow birdhouse gourd vines to climb and ramble over a fence. A fence offers the benefits of cleaner, straighter necked gourds than those rambling on the ground, with no need for a trellis structure. Move wandering vines into the fence row to keep them under control.