Cucurbita Genus: Squash and Pumpkins

8/7/2024

Cucurbita Genus: Squash and Pumpkin Species

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Cucurbita Genus: Squash and Pumpkin Species

Pictured clockwise starting from the upper left is Delicata squash, Jack-Be-Little gourd, Gill's Golden Pippin squash, Acorn squash, Sweet Dumpling squash, and Buttercup squash. All are C. pepo species, except for Buttercup which is a C. maxima.

Cucurbitaceae Family

The Cucurbitaceae family includes squash, pumpkins, gourds, melons, cucumbers, bitter melons, and luffa. The Cucurbita genus, the focus of this blog post, includes squash, pumpkins, and gourds. Species in the Cucurbita genus include C. argyrosperma, C. ficifolia, C. maxima, C. moschata, and C. pepo. Below I review each species including commonly grown varieties and conclude with a discussion of cross-pollination concerns if you wish to save seed.

Cucurbita argyrosperma

C. argyrosperma species include the Cushaw-type squash. The most well-known variety in the United States is the Green-Striped Cushaw. Other varieties found in the United States include the Japanese Pie Pumpkin and Orange-Striped Cushaw. This species originated from Mexico and was previously known as C. mixta.

Cucurbita ficifolia

C. ficifolia is an edible squash, not well known in the United States. It has many common names including fig-leaf gourd, Malabar gourd, Asian pumpkin, and more. It is commonly grown in South America, Mexico, Asia, and Africa.

Golden Hubbard squash a variety that belongs to the C. maxima species.

Cucurbita maxima

The C. maxima species includes squash varieties well-known in the United States including Boston Marrow, North Georgia Candy Roaster, Hubbard (both blue and golden), Red Kuri, Turk’s Turban, Buttercup, Banana Squash, Jarrahdale Pumpkin, Kabocha, Lakota, Rouge Vif D’Etampes (also known as the Cinderella Pumpkin), Galeux d’Eysines (also known as the Peanut Pumpkin), and Marina Di Chioggia. This species also includes giant pumpkins, some of which can reach well over 2000 pounds! The giant pumpkin varieties are derived from Dill’s Atlantic Giant, developed by Howard Dill, a Canadian pumpkin breeder.

A Black Futsu squash, a variety of the C. moschata species.

Cucurbita moschata

A Tromboncino squash, a C. moschata species.

C. moschata is a commonly grown species in the United States and includes the Butternut and Cheese varieties such as Long Island cheese and Musquee de Provence. It also includes Seminole, Black Futsu, and Tromboncino (Zucchino Rampicante) varieties. The tromboncino varieties are unique in that you can eat them when young and tender, like zucchini, or allow them to mature and eat them like winter squash. C. moschata is generally used to make canned pumpkin pie mix in the United States. If you live in an area with squash vine borers, this species also tends to be more resistant than other species since it has a solid, not hollow, stem.

Cucurbita pepo

A Black Beauty Zucchini, a variety in the C. pepo species.

The species C. pepo includes many well-known varieties including winter and summer squash. Winter squash varieties include Acorn, Sweet Dumpling, Delicata, Spaghetti, and pumpkins commonly used for pies or Jack-o’-lanterns. Pumpkins in this species include Connecticut Field, New England Pie, Winter Luxury, Early Giant, Big Max, and Howden. The hulless seed varieties, such as Kakai, are also C. pepo. Summer squash varieties include Cocozelle, Crookneck, Straightneck, Scallop, Patty Pan, Pool Ball, and the many Zucchini varieties. C. pepo also includes most non-edible, small, decorative gourds, including the winged and warted gourds and the small gourd-type pumpkins, such as Jack-be-Little. One exception is the larger gourds such as Birdhouse, Bottle, Dinosaur, and Caveman Club which belong to a different genus, Lagenaria. C. pepo is unfortunately very susceptible to the squash vine borer due to its hollow stems.

A classic field pumpkin (left) and decorative, non-edible gourd (right). Both are different varieties of the same C. pepo species.

Cross-Pollination

You do not have to worry about cross-pollination in any plant unless you are interested in saving seed (except corn since you eat the seed). Pollination by another variety of the same species will only affect the next generation if you save the seed and plant it the following season. It will not affect the fruit (i.e. tomato) of the plant. If you are interested in saving seed the general rule is that varieties in the same species can cross-pollinate. For example, if you plant acorn squash and a sugar pie pumpkin, they are both C. pepo and likely will cross-pollinate as they are insect-pollinated and have separate male and female flowers. However, it is unlikely that a C. pepo variety, like acorn squash, will cross with a C. maxima variety, such as a Hubbard squash since they are two different species. Squash and pumpkins will also not cross with melons, including cantaloupe and watermelon, or cucumbers, as they are also different species.

If you wish to grow multiple varieties of pumpkins and squash from the same species, and you also wish to save seed, you will either need to separate varieties by a half to one mile or net the plants to prevent insect pollination and hand pollinate.