Harvest gourds when the stems turn brown and dry. If possible, harvest them before frost hits, though mature hardshell gourds (Lagenaria) can withstand a light frost. Cut the gourds from the vine, leaving an inch or two of stem attached. Discard rotten, bruised, or immature gourds. These are more likely to decay. Wash the harvested gourds with soap and water. A dip in rubbing alcohol or a 10 percent bleach solution will help remove surface molds that may cause rot. Dry the surface and place the gourds in a dark, well-ventilated area for a week or so of surface drying to harden the rind and set the color. Make certain the gourds do not touch one another; use a slatted tray or screen to allow air to circulate all around. Discard any gourds that develop decay, mold, or soft spots. Internal drying takes at least 4 additional weeks in a warm, dark, well-ventilated room. Turn the gourds periodically to promote even curing. Wipe off surface molds that may appear. Discard any gourds that decay, shrivel, or become misshapen. When the seeds rattle inside, drying is complete.