The second group includes the hard, thin-shelled “utility” bottle/birdhouse gourds belonging to the Lagenaria genus. The Lagenarias have smooth stems; soft, large leaves; and white flowers. The Lagenaria gourds are tan to brown when mature with long, narrow hard stems and have many distinct shapes and sizes. This includes such unique types as the caveman’s club, calabash, dolphin (maranka), swan gourd, Corsican flat, apple, drum, bottle, and small and large dipper types.

Days to maturity will vary by species and variety, ranging from 90 days from seed for the small Cucubita gourds to over 120 days for Lagenaria types. As the weather cools in the fall, additional time in the field may be needed.

The Cucurbitaceae family is tropical and sub-tropical in origin, and does not tolerate cold soils or cool growing temperatures. Even a light frost will significantly damage foliage and impede crop development. Planting should be delayed until the late spring when soils have warmed. When making planting date decisions, average fall frost date and marketing period should be considered along with varietal days to maturity. Proper timing of the planting to allow the crop to mature before frost is of particular importance. These factors should also be considered when making decisions to direct seed or transplant the crop in the field.

Both species have sprawling growth habits and require room to spread. Lagenaria types readily climb by long twining tendrils, and are often grown supported by a trellis. All cucurbits are monecious (separate male and female flowers on the same plant), and require insects (bees) to transfer pollen and to set fruit. Night-flying moths are also known to pollinate Lagenaria.

Lagenarias have a long growing season and need early planting to mature by the end of the season. Otherwise a large percentage of fruit will be green at first frost. In comparison to Cucurbita types, Lagenarias are more sensitive to cold, and more adapted to consistent warm weather conditions. Soils should be at least 65°F prior to planting. To speed growth and development, use transplants instead of direct seeding.

Lagenarias are vigorous growers and develop large plants. Vines may reach 20 to 30 feet in length. Rows should be 10 to 15 feet apart, with plants set five to six feet apart in the row. Because of the price of seed and their vigor, multi-plant hills are not recommended. The above spacing will require 500 to 700 plants or seeds per acre. For the bottle and dipper types, trellising will allow fruit to hang, resulting in a straight neck. If allowed to grow on the ground, the fruit will curve in various directions.

The ideal soil pH is in the range of 6.5 to 7.0. A soil test should be conducted to determine available phosphorous (P), potassium (K), and magnesium (Mg) levels. Low P and K soils require amendment to increase levels of these nutrients to moderate levels per soil test standards. As a starter fertilizer, at least 50 pounds of P and 100 pounds of K per acre should be applied in most soils. Gourds are sensitive to low levels of Mg, and soils should test to 100 to 125 pounds per acre of this nutrient. If not, Mg should also be supplemented preplant. Because of significant vine and leaf growth, gourds respond to fertile soils and applied nitrogen (N). At planting apply 50 to 60 pounds of N per acre along with P, K, and Mg amendments. Vines will begin to run or spread in three to five weeks after planting. An additional side dressing of 30 to 40 pounds of N per acre should be applied to keep plants vigorous. With drip irrigation, supplemental N can be injected and split-applied at two- to three-week intervals. By late summer, nutrients and water should be reduced. This will permit plants to slow growth and recently set fruits to mature and harden off.

Supplemental irrigation on both tilled and no-till fields can be beneficial during dry periods and increases yields. Irrigation should supplement rainfall with an average of one to two inches per week. Water should be withheld during the end of the season to hasten maturity.

For small-scale plantings, Lagenaria gourds will respond to vine pruning by increasing the number lateral shoots (runners) and of female flowers that develop into fruit. Vines should be tipped back once with a mower or by hand when they reach eight to ten feet in length.

Average yields for the small Cucurbita gourds will be from 20,000 to 30,000 fruit per acre. For the Lagenarias, expect a range of 2,000 to 5,000 gourds per acre.

To assure quality, timely harvest and proper handling and curing are necessary. Cucurbita gourds are frost sensitive when mature, and should be harvested before the first predicted frost event in the fall. Full-color development, and the drying and hardening of the stem and outer skin are harvest indicators. Immature gourds willnot cure well, and are best left in the field. Harvested fruit with spots of decay or damage or that are too immature should be sorted and discarded. Depending on planting date, a range of fruit maturity is typical, as plants will continually set new fruit over the season. Where days to maturity are observed, a large percentage of fruit should be mature on the vine before frost; a few may have passed ideal harvest stages.

At maturity, Lagenaria gourds will begin to change from bright green to pale green and eventually to tan. The stem will also become more rigid and dry. In contrast to the Cucurbita types, once fruit has reached a mature- or firm-green stage, with proper curing they will usually dry without decay or shrinkage. Some of the Lagenaria types, such as the speckled swan gourds are harvested green and are marketed in a timely manner similar to Cucurbitas. If the season allows, it is best to leave them in the field until they are as near to maturity as possible. Frost may affect the final tan color, surface pattern, and seed viability, but not the shell integrity of a mature Lagenaria.

Harvest all gourds with one to two inches of stem intact. An intact stem enhances value. Care should be taken not to bruise or scrape them, and always clip, not tear the fruit from the vine. Freshly harvested gourds can be washed in warm, soapy water, using a soft brush to clean warty types. A light pressure rinse may suffice, followed by a dip in clean water with a household disinfectant, rubbing alcohol, or a light bleach solution (1 percent to 2 percent). This step is important to reduce fungi and bacteria on the surface that can find entry through surface injuries.

Both types are cured under similar conditions; however, the Lagenaria group requires several months to cure before it can be utilized while the Cucurbita group needs only a few weeks to properly cure for use. When cured properly, Lagenarias will last for many years; the Cucurbita types six to nine months before the colors begin to fade.

Curing is a two-step process, involving a short period for surface drying, and a second, longer internal curing period. Surface drying hardens the outer skin and sets the colors for the Cucurbita types. Spread out cleaned gourds on a screen or newspapers in a well-ventilated, partially sunny area, and turn them regularly. Discard any that shrivel or develop soft spots. Surface drying can take from a few days to a week.

Gourds can also be cut from plants and initially left to dry in the field. This is often done with Lagenaria types. Uncleaned, field-dried gourds should be rinsed and wiped down with a disinfectant solution before continuing with internal curing. Harvest bins, packing boxes and shipping crates are not advisable places for curing, as lack of air movement will result in rotted gourds.

Internal curing requires a warm (80°F), low-light, and dry location. Warmth encourages rapid drying, darkness prevents color fading, and dry conditions discourage mold. Artificial heat can be used, but without ventilation it can lead to faster mold development. A well-placed fan can help speed the process. Cucurbita gourds will need an additional two to four weeks to final cure, while Lagenaria species may take up to three months to fully cure; longer if they were green at harvest. Seeds rattling inside indicate the gourd is fully dry. Prior to shipping or display in the market, sort cured Cucurbita gourds one last time for decay, as potentially immature fruit may have been harvested in the rush to beat frost or get them to market.

During curing of Lagenaria, it is common to see mold growing across the surface. The mold can leave desirable, unique patterns as it breaks down the waxes and upper skin layers, yet the fruit wall integrity is not diminished. Lagenaria gourds are highly resistant to decay and to an extent can be exposed to the elements and variable temperatures.
Long-term winter exposure can result in cracking and weaken gourds and is not advised. At a minimum, these gourds should be stored in a barn or well-ventilated shed. Regular wiping with alcohol or a light bleach solution can discourage mold growth if a solid tan color is desired for these types.

Following curing, gourds can be waxed, lacquered, or painted to extend their life and improve appearance. For colored cucurbita types, well-cured gourds may last three to four months without this treatment while coating with wax or varnish will extend storage life and color retention to six to eight months. Paste wax will provide a soft luster to the gourd, while varnish or lacquer adds a hard, glossy shine. Dip waxes used for fruit such as apples and oranges can also be used on gourds to extend life, and some commercial buyers require this treatment.

Gourds can be sanded smooth and painted as well, which can greatly extend the life of the Lagenaria types used outdoors, such as for a birdhouse. Often they are painted gold or silver for table displays.

Lagenaria types have many utilitarian uses. The crook-necked types can be cut into dippers and scoops; the larger drum gourds used as storage vessels. For birdhouses, drill a small hole through the top for a hanging cord. On the side, cut a hole large enough to accommodate wrens, barn swallows, or other small birds. Shake out the dried seeds. A small hole drilled in the bottom will help drain any rainwater that finds its way into the house. These natural-gourd birdhouses can last for many years.

You can save seeds from grourds, but they do cross pollinated very easily, to ensure that seed is true, isolation or blocking of the planting by variety should be practiced to limit crosspollination potential. One of the best methods to ensure true seed is to directly hand-pollinate selected flowers as they open, with a known pollen source.
Use a ribbon, flag, or other marker to keep track of these fruit through the harvest period. Fruits should be fully mature before seeds are extracted. Separate seeds from the pulp and spread in a thin layer on cloth or newspaper until dry. Store seed in a cool, dry place. Under ideal conditions seed may remain viable for three to five years.