In the world of vegetable growing, gourds have earned a secure niche. These members of the cucumber, melon, and squash family are grown for their decorative and utilitarian qualities rather than for their edible ones. The best known and most versatile are the hard-shelled gourds (Lagenaria siceraria) , so named because their shells dry to a hard surface that can be treated for many different uses. These familiar, durable gourds are used around the world to make everything from containers and utensils to water dippers, smoking pipes, musical instruments, and works of art.
There are four main types of hard-shelled gourds. Basket gourds have large, bulbous bases and no neck. Bottle gourds develop two distinct bulbous ends with a constriction between them. Dipper gourds feature long, thin necks and a small bulblike base at the blossom end. Snake or siphon gourds have long, tubular necks and no bulbous base. Within each of these types are many variations, each with its own particular shape. Before you plant, decide which is the right kind for the uses you have in mind.
Plant and grow hard-shelled gourds as you would winter squash. The sprawling plants grow best in warm-summer conditions, requiring 120 to 140 frost-free days to mature. To grow these gourds to maturity where the growing season is 120 days or less, start seed indoors and use season-extending devices, such as floating row covers, in fall if necessary.
In cool-summer climates, preheat the soil with black plastic mulch four weeks before your last frost date, when you can set out seedlings. Start seedlings in individual pots indoors at the same time you set out the plastic.
Where summers are warmer and longer, sow seeds outdoors after all danger of frost has passed, in full sun and in soil amended with compost or manure. Sow two seeds in hills spaced 8 feet apart, or sow in rows with plants spaced 4 feet apart. The seeds have particularly thick skins; to hasten germination, nick them with a file before planting to help water penetrate the seed coat.
Cover the seedlings with a floating row cover, especially during chilly spring nights. Keep plants well watered. In warm areas, preserve soil moisture with a 2- to 4-inch layer of hay, straw, or leaf mulch. When the vines begin to run, fertilize with 3 pounds of 10-10-10 per 100 square feet of garden, or use fish emulsion. Once the gourds have set, don't apply high-nitrogen fertilizer.
Gourds are slow starters, but once the heat of summer hits, the vines grow by leaps and bounds. When vines growing on the ground reach 10 feet long, snip off the growing tip to stimulate the formation of side shoots (laterals). Gourds, like all squash family crops, produce separate male and female blossoms on each plant, and these shoots produce the most female flowers, so the more branching, the more fruits. Pruning also keeps the vines under control.
Some gourds, such as the bottle and dipper types, grow best on trellises. Let the vines climb naturally, and position the fruits so they can hang unobstructed. Trellised vines are not only attractive, but they produce straighter and cleaner fruits than vines grown on the ground. Be sure the trellis is sturdy, especially in windy areas, since an individual plant can be huge--vining up to 40 feet.
Some of the heavier basket-type gourds may need to be supported with a sling; old pantyhose are an inexpensive means of support. On the other extreme, some kinds of mini gourds can be grown in containers. Although smaller, they're still aggressive growers, so you'll need to be more diligent about trellising and watering.
On a trellis, remove all the side shoots, and train the main stem up the trellis post. Once it reaches the top of the trellis, clip the main stem and allow the laterals to form and fill out the top of the trellis.
Gourds on trellises are easy to shape by tying soft, stretchy strings around young fruit and then bending or constricting them by applying slight pressure. Some gourds can be placed in molds or jars and will take the shape of the container. Be careful to select the right-sized container for the mature size of the gourd, or the container-bound fruit will be damaged.
Hard-shelled gourds produce large white flowers that open at night. It's not clear which insects pollinate these flowers, but if your baby gourds are shriveling and dropping off the plant, you may need to hand-pollinate the flowers in the evening shortly after they open. Some growers like to let only a few gourds set and then snip off all others, since the first fruits to set produce the largest gourds with the thickest skins. In cool climates, snipping off late-setting fruits will redirect the plant's energy to maturing the first few fruits before frost.
Pests and diseases that affect gourds are similar to those afflicting other squash family crops; they include downy and powdery mildew, cucumber beetles, vine borers, and aphids. Generally, the techniques and products recommended for controlling these pests on cucumbers and melons will also be effective on gourds.
Harvest hard-shelled gourds only after they mature on the vine. They are ready when the stem and tendril next to the gourd have browned, and the gourd's skin has begun to turn an ivory color and feels firm. Cut off the gourds, leaving at least 2 inches of stem on the fruit.
Mature gourds can withstand frost, but it may affect the skin color. After curing, gourds harvested before frost tend to be tan or mahogany, while those harvested after frost will take on a curly maple appearance. It's best to pick the gourds as soon as the vines are dead (especially on trellised vines that may not be able to support heavy fruits), and to move the gourds indoors to a dry, well-ventilated place for curing and drying.
Bring harvested gourds into a cool (50° to 60° F), well-ventilated room. Clean away any soil from the surface, and wipe the gourds with a mild bleach solution (1 ounce liquid bleach to 2 quarts water). Don't try to save any gourds that have cracked or broken skin, since they will rot eventually. To cure the gourds, place them, not touching, on a wire-mesh or slotted tray out of direct sun.
Depending on the gourd's size, shape, and skin thickness, it can take up to six months to completely dry inside. As gourds dry, they may develop a fuzzy white growth on the shell. This is natural and, as long as the shell isn't soft, there's no cause for alarm. You can remove the mold by periodically wiping the shell with the mild bleach solution, or leave the mold to form interesting patterns on the skin. The gourd is finished drying when it feels much lighter and the outer skin peels away to reveal a brown or tan inner shell. You will also hear the seeds rattle inside.
To hasten the drying process, slice off the top of the gourd right after harvest, and scrape out as much of the seedy pulp as you can without harming the shell. Then fill the inside with water, and let sit for a week. The remaining flesh will turn gelatinous and mucky but will be easier to scrape out.
Transforming an ungainly gourd into a graceful ornament is easier than many gardeners imagine.
Each of the surface treatments described below requires little skill; only a few basic hand tools and some supplies, available from a craft or hardware store, are necessary. Before applying any surface treatment, be certain that the gourd is properly cured.
Make a leaf bowl by cutting a leaf design out of the gourd with a hand saw. Scrape out the pulp, and sand the soft interior to a smooth finish, then cover it with a decoupage of leaf designs cut from decorative tissue paper. Stain both the inside and outside surfaces before varnishing the whole bowl.
Apply delicate gold patterns to gourds with a pen that produces a fine, opaque line for maximum coverage and control. For added effect, glue gold-colored cord around the rim.
Create a burnished look to your gourd by first darkening it with black shoe dye, then covering it with gold shoe polish. As a final touch, add black leather trim and gold beads.
Make a simple pitcher by staining a gourd with white shoe polish, which highlights the natural patterns on the gourd's surface. Then glue nylon cord around the top rim and the bottom, leaving enough between the top and bottom to form a handle. The cord at the bottom acts as a base.
Make a pitcher from two gourds: a bottle and a dipper, trimmed with a crafting knife and handsawn to fit together. File and sand any rough edges, glue the parts together and fill in any remaining seam with putty. Create a coppery surface using an acrylic metallic paint rubbed with black shoe polish.
Use marking pens to decorate gourds. This allows for flexibility, freeform design, and many color choices. Unfortunately marking pens, even permanent kinds, will fade over time.
To learn about growing and using the many different kinds of ornamental gourds, consult Gourds in Your Garden: A Guidebook for Home Gardeners, by Ginger Summit (Hillway Press, 1998; $20); and The Complete Book of Gourd Craft, by Ginger Summit and Jim Widess (Lane Books, 1996; $27).
Photography by Sabin Gratz/National Gardening Association and Suzanne DeJohn/National Gardening Association.
Article published on June 23, 2008.