Cucurbita and Lagenaria gourds are ready to harvest when the fruit develop a hard rind. You may wait until the stems begin to dry and turn brown or when the leaves start to die. Harvest the hard-shell gourds before frost. The Lagenaria (bottle) has white flowers and will tolerate a light frost. If subjected to a light, vine-killing frost, some Lagenaria will have a maple color when cured and finished. For a tan or mahogany finish, cut the fruit before frost. Cucurbits have yellow flowers and are more frost sensitive.
Harvest by cutting the stems at the vine end. Never twist or pull to harvest. Stems may fall off when dry.
After harvesting, wash the fruit with warm, soapy water. Then rinse in warm water to which a small amount of household disinfectant has been added. Some people like to rinse them with warm water, wipe dry, then wipe again with a cloth dampened in rubbing alcohol. A bleach dip made from 1 ounce bleach in 2 quarts of water may be used to bleach colors from the gourds as well as sterilize the surface. After using this dip, dry the gourds thoroughly. All this cleaning stops mold from discoloring the cuticle.
Discard any diseased, bruised or immature, soft-skinned fruit. Then place clean, dry fruit in an open-mesh bag hung in a warm, dry, well-ventilated place. Avoid placing fruit in strong sunlight because colors will fade where exposed. Check carefully for any signs of decay, and remove damaged fruit from the bag immediately.
Curing takes one to six months, depending on the type, size and use of fruit. Lagenarias take longer to cure. First, the outer skin hardens and the surface colors set; this phase takes one to two weeks.
Internal drying takes at least another four weeks. This stage may be hastened by drilling or pushing a wire through the blossom end of the gourd to create a small hole.. If the gourd is to be used as a utensil or vessel, holes are not desirable. Turn the fruit occasionally and check for shriveling, soft spots and uneven drying.
Fruits to be made into utensils and bird houses can be prepared near the last stage of drying. If completely dry, they may crack and shatter when being carved.
The rattle of the seeds when the gourd is shaken indicates adequate curing for bottle gourds. Once well cured, the fruit may be waxed, shellacked or painted. A high-grade transparent furniture or floor wax is preferred to shellac or varnish because the latter may change the natural color. A glossy surface does not have a natural appearance. Paints should be washable if the gourd is to be outside.
Hard-shell Lagenaria gourds can be smoothed and polished with a very fine grade of steel wool or sandpaper. After sanding, wipe with a clean cloth dampened with alcohol or turpentine. Allow to dry thoroughly before waxing or adding any decoration.
In addition, periodic waxing or painting will help preserve the fruit.