Crop origins

Cushaw squash has been grown in Kentucky for thousands of years. The Commonwealth Cushaw Project began in Eastern Kentucky, where cushaw squash are an important traditional crop that is still still grown in many gardens for sharing and sale at local markets.

The following content was adapted from the Wikipedia article Cucurbita argyrosperma. Unlike other parts of this guide that are offered without a Creative Commons “Share Alike” clause, the Wikipedia content is licensed with a CC BY-SA license.

Like the other Cucurbita squash, all cushaws are native to the Americas. The first example of a Curcubita species in cultivation is C. pepo which is believed to have been cultivated by inhabitants of Guilá Naquitz cave between 10,000 to 8,000 years ago.

Most squash traditionally called cushaws are botanically classified as Cucurbita arygrosperma, but there are some cushaws of species C. moschata. This guide is focused on cushaws of species C. argyrosperma, including interspecific hybrids with demonstrable arygrosperma traits.

The species is believed to have originated in Mexico, from its wild sororia form. In precolonial America, archaeological remains have been found as far northward as the cultures of the Eastern Agricultural Complex. The extant native range of the wild sororia type is from northern Mexico through Central America to Nicaragua.

The earliest known possible archaeological records of C. argyrosperma are 8,700-year-old phytoliths in the Central Balsas River valley in Guerrero, but these remains are considered ambiguous. The earliest unambiguous specimen is a C. argyrosperma peduncle that has been dated to approximately 5,100 years ago, from the Ocampo caves.

Genetic evidence centers the domestication of C. argyrosperma in what is now Jalisco, Mexico. Other evidence suggests that following domestication and before European contact, C. argyrosperma diffused northward into what is now the eastern and central United States before European contact. C. argyrosperma seeds have been recovered from Late Mississippian archaeological contexts in Arkansas that suggest domesticated C. argyrosperma was established in that region 1,310–623 years ago.

Domestication involved genetic changes to attributes related to growing, handling, and using the plant. C. argyrosperma is thought to follow a domestication pattern similar to other Cucurbita, beginning with reduction of bitterness and an increase in seed size. In C. argyrosperma, attributes affected by domestication and selective breeding include:

  • reduction in bitter taste from cucurbitacins
  • increase in the size of fruits and seeds
  • more uniform germination time
  • reduced size and abundance of urticating trichomes (hair)
  • diversification of fruit shape

Selected references

”Neglected Crops: 1492 from a different perspective.” Food and Agriculture Organization of the United Nations, 1995, pp. 63-67.https://openknowledge.fao.org/items/84aafc6d-d859-4e0f-966c-a0e38b38f55d. Accessed 25 Jan. 2025.

Fritz, Gayle J. “Precolumbian Cucurbita Argyrosperma Ssp. Argyrosperma (Cucurbitaceae) in the Eastern Woodlands of North America.” Economic Botany, vol. 48, no. 3, 1994, pp. 280–92. JSTOR, http://www.jstor.org/stable/4255642. Accessed 25 Jan. 2025.

Kistler, Logan & Newsom, Lee & Ryan, Timothy & Clarke, Andrew & Smith, Bruce & Perry, George. “Gourds and squashes (Cucurbita spp.) adapted to megafaunal extinction and ecological anachronism through domestication.” Proceedings of the National Academy of Sciences. 2015. http://doi.org/10.1073/pnas.1516109112.

Lira, Rafael, and Javier Caballero. “Ethnobotany of the Wild Mexican Cucurbitaceae.” Economic Botany, vol. 56, no. 4, 2002, pp. 380–98. JSTOR, http://www.jstor.org/stable/4256609. Accessed 25 Jan. 2025.

Merrick, Laura C. “Systematics and Evolution of a Domesticated Squash, Cucurbita Argyrosperma, and Its Wild and Weedy Relatives.” Biology and Utilization of the Cucurbitaceae, edited by DAVID M. BATES et al., Cornell University Press, 1990, pp. 77–95. JSTOR, http://www.jstor.org/stable/10.7591/j.ctvr7f7q4.11. Accessed 25 Jan. 2025.