Just as humans domesticated animals thousands of years ago, they also cultivated plants to meet their needs. Among the oldest domesticated plants, one stands out for its distinction of being utilitarian, decorative and, in general, inedible: the gourd.
Many cultures, including Native Americans, have cultivated gourds for thousands of years. There are a few varieties harvested for consumption today, mostly in Asia, and smoky-tasting white gourd juice is a common beverage sold in China. However, gourds are grown primarily for use as utensils and storage containers. You can find ornaments, stringed musical instruments and drums made from gourds. In the United States, many people craft birdhouses for purple martins from them.
Evidence suggests that early man domesticated the bottle gourd, a plant native to Africa, for use as a container around 10,000 B.C. Some experts think that the shape of today's clay pottery is modeled after certain gourd varieties.
Recent research into bottle gourds found throughout the Americas has resolved a long-standing mystery. Initially, archaeologists believed that the African bottle gourd probably floated across the Atlantic Ocean to the Americas. But after examining its DNA, they found that the samples matched those found in Asia, not Africa. They concluded that early migrants from Asia brought the bottle gourd to the Americas.
A member of the Cucurbitaceae family, the same as cucumbers, melons, squash and pumpkins, the gourd is the hollow dried shell of a fruit. There are three general types: the cucurbita, or ornamental gourd; the lagenaria, or large utilitarian gourd; and the luffa, or vegetable sponge.
The cucurbita include the colorful, variously shaped ornamental gourds used frequently in autumn arrangements. These plants produce large orange or yellow blossoms that bloom in the daytime. Cultivars include 'Aladdin's Turban,' 'Striped Crown of Thorns,' 'Bicolor Pear,' 'Cannon Ball,' 'Basket Ball,' 'White Egg' and 'Small Spoon.'
The lagenaria group includes the martin or birdhouse, bottle and dipper gourds. These plants produce white blossoms that bloom at night. Lagenaria gourds are green on the vine and turn brown or tan, with thick, hard shells when dry.
Cultivars include 'Bird House,' 'Long Handle Dipper,' 'Caveman's Club,' 'Swan' and 'Martin House.'
Luffas have an outer shell that is removed easily to expose a tough, fibrous interior that can be used as a sponge. They produce numerous vines with yellow blossoms and have the longest growing season of all gourds.
Gourds are warm-weather crops with a long growing season of 100-180 days. Start seeds indoors four weeks before transplanting outside. Plant seeds in individual containers because the roots will not tolerate being disturbed during transplanting. Scarify (scratch the surface of) luffa seeds to germinate. Plant seeds or seedlings in full sun and well-drained soil after all danger of frost has passed and soil and air temperatures have warmed. Space 2 feet apart in rows 5 feet apart. Gourd seeds can rot before germinating if planted in cold, wet soil.
Gourds are vigorous growers and will readily climb a trellis, fence or arbor. Luffa plants require a sturdy support to keep the developing fruit off the ground, which will discolor the gourd. Water the plants consistently and fertilize them when the vines begin to spread, about three to five weeks after planting.
Each gourd plant produces male and female flowers before it sets fruit. Bees pollinate day-blooming gourds, and moths, night-blooming gourds.
Gourds are ready for harvest when the stems dry and turn brown. Cut gourds from the vine with a few inches of the stem attached. After harvesting, clean with soap and water, dry them and apply rubbing alcohol to the surface.
Gourds can take one to six months to dry completely, depending on type and size. The outside will look dry within a week, but it takes a minimum of four weeks for the inside to cure. Periodically turn the fruit to discourage shriveling and promote even drying. The gourd is cured when it becomes light -- weighing a few ounces -- and you can hear the seeds rattling inside. A gourd that is not completely dry inside will give off a bitter smell when cut.
When dried, the shell has a wooden appearance. It is essentially cellulose that has no grain, varying in thickness from paper-thin to well over an inch. This hard outer surface lends itself to artistic carvings and other decoration.
After curing, you can smooth and polish the surface with very fine steel wool or sandpaper. Then, treat it with rubbing alcohol, allow it to dry, and wax or shellac it for the final finish. Or, you can paint, dye, wax, carve or decorate cured gourds before finishing them.
If you want to cut open a dried gourd to make a bowl, use either a craft knife or a jigsaw. This can be challenging, however, and the resulting dust it creates can be hazardous to your respiratory system. Be sure to take precautions, and cut in a well-ventilated area.
Luffa gourds need specific harvesting and processing techniques to produce high-quality sponges. Harvest the fruit when the outer shell is dry, the gourd is lightweight and you can hear the seeds rattling inside. Remove the stem end of the gourd and shake out the seeds from the center cavity. Soak in warm water until the outer skin softens to the point where it can be removed easily. Then, soak the fibrous sponge in a solution of one part bleach to nine parts water to obtain the desirable creamy-white appearance. Rinse in clear water and allow to dry before using.
For more information about cultivating and using gourds, contact the American Gourd Society at www.americangourdsociety.org. If you want to learn about decorating your own gourd or to buy finished products, check out Meadowbrook Farm in Carlisle, Pa., at www.gourdshop.com.
Susan Biddle is a Penn State Master Gardener. Columns by master gardeners will sometimes appear in place of the Garden Q&A by Sandy Feather, a Penn State Extension educator.