Ornamental gourds make attractive birdhouses once they are dried and prepared. The birdhouse gourd is most often used for this purpose, but bottle gourds can be used as well. The gourds used for birdhouses are part of the Langenaria family. These have a smooth outer shell that dries hard after it is properly cured. Proper drying is vital, otherwise the walls of the gourd are weak and the gourd may rot once it is exposed to the elements outdoors.
Wash the gourd in warm, soapy water. Use a soft-bristled brush to remove stuck-on dirt. Mix one part bleach with nine parts water and rinse the gourd in this solution to disinfect it.
Place the gourd on a sheet of newspaper in a well-ventilated area, either indoors or outside, in bright sunlight to dry. Turn the gourd once a day so all sides dry evenly. Dry the gourd in this manner for one week or until the surface feels hard and dry.
Move the gourd to a dry dimly-lit, 80 degree F room indoors after the surface has dried. Place the gourd on newspaper or set it in a shallow box that is large enough that air still circulates around it.
Dip a cloth in rubbing alcohol and wipe off the surface of the gourd if mold begins forming during this final curing. Alternately, wipe off the mold after the gourd is completely cured, as it leaves behind a discolored pattern that is often attractive.
Shake the gourds once a month to check for dryness. Gourds are fully cured and ready to make into a birdhouse once you hear the seeds rattle inside. Gourds may take up to six months to dry completely, according to the Virginia Cooperative Extension.