// SPECIES PROFILE · CROP · HEIRLOOM · HEAT & BORER TOLERANT

Cushaw Squash

Cucurbita argyrosperma

Cushaw is the squash that actually finishes a NE Oklahoma summer. Domesticated in southern Mexico thousands of years before maize reached the Cross Timbers, it is the one cultivated Cucurbita that shrugs off squash vine borer, walks past 100°F afternoons, and yields 8–15 lb crookneck-shaped fruit when 'Howden' pumpkin and 'Butternut' winter squash have already collapsed. The Tennessee Sweet Potato, Green-Striped Cushaw and White Cushaw heirlooms are the three-sisters squash of the southern Plains — an interplant with corn and cowpea documented in Choctaw, Cherokee, Caddo and Wichita farms across what is now eastern Oklahoma. Mild buff-orange flesh, excellent for pies, soups and animal feed; seeds large, flat, silvery-tan, and snackable.

// QUICK FACTS

Family: Cucurbitaceae (cucurbit family)
Group: Crop — warm-season annual cucurbit
Native range: Domesticated in S Mexico ~7,000 yrs ago
USDA hardiness: Annual; frost-free 100–120 day window
Mature size: Vines 12–25 ft · fruit 8–25 lb
Sun: Full sun (8+ hrs)
Soil: Deep loam with compost; pH 6.0–7.0
Water: Average; deep weekly watering at flowering & fruit-fill
Days to maturity: 100–120 from sowing
Pollination: Monoecious; insect-pollinated (squash bees, bumblebees)
Vine-borer resistance: High — tough, often hollow stems
Storage: 3–6 months in cool dry pantry once cured
Seeds per fruit: 200–500 large flat silvery seeds
Wildlife: Squash bees (Peponapis pruinosa) are obligate visitors

Cushaw squash (Cucurbita argyrosperma) — characteristic crookneck fruit with green stripes and pale ground — *Cucurbita argyrosperma* — the borer-resistant Mesoamerican squash that has been a staple of NE Oklahoma three-sisters gardens since pre-contact times. Photo via Wikipedia / Wikimedia Commons.

Identification

[ field key — vine · leaf · flower · fruit shape · seed ]

Vine & stem

A strongly trailing annual vine that grows 12–25 ft in a single season under good conditions. Stems are five-angled, ribbed and bristly, often somewhat hollow at maturity (the diagnostic feature that makes the species relatively unattractive to squash vine borer larvae, which prefer the solid-pith stems of C. pepo). Adventitious roots form at leaf nodes where vines touch moist soil — useful for recovering from borer damage and for harvesting moisture across a long vine.

Foliage

Leaves are large (8–14 in across), shallowly 5-lobed, nearly orbicular, with bristly hairs on petiole and underside. They are not the deeply incised, silver-mottled leaves of zucchini and pumpkin (C. pepo) nor the soft fuzzy lobed leaves of butternut (C. moschata) — cushaw leaves are coarser, more rounded, and less variegated. Tendrils are simple to branched, opposite each leaf.

Flowers

Monoecious: separate male and female flowers on the same plant, both deep yellow-orange and trumpet-shaped (5–6 in across). Male flowers are produced first and in larger numbers on long pedicels; female flowers (with a tiny squash-shaped ovary at their base) follow about two weeks later. Pollinated entirely by insects — primarily the native squash bee (Peponapis pruinosa), a specialist whose entire life cycle is tied to the genus Cucurbita, plus bumblebees and honeybees.

Fruit, seed & lookalikes

The fruit is the unmistakable feature: a large pale-tan or green-and-cream striped crookneck, 12–24 in long, with a bulbous seed cavity and a long curved neck of solid flesh. Mature fruit weighs 8–25 lb. Seeds are large, flat, silvery-cream — the species name argyrosperma means "silver-seeded". Easy to distinguish from C. pepo (zucchini, pumpkin, acorn squash — angled stems, lobed leaves), C. moschata (butternut, Seminole pumpkin — smooth ribbed stems, soft fuzzy leaves) and C. maxima (banana, hubbard — cylindrical corky stems).

Habitat & Range in NE Oklahoma

Cushaw is not native to North America — it was domesticated in southern Mexico roughly 7,000 years ago, with the closest wild progenitor (C. argyrosperma ssp. sororia) still found in the Balsas and Tehuacan basins. From its Mesoamerican origin it spread north through trade and migration along the river systems of the southern Plains, reaching the Caddoan and Wichita peoples of present-day Oklahoma in the centuries before European contact. By the early historic period it was a standard three-sisters squash across the southeastern Woodlands and the southern Plains, including in the gardens of the Choctaw, Cherokee, Creek and Caddo communities removed to Indian Territory in the 1830s.

For NE Oklahoma it is the right squash for the actual climate: the standard New England-style pumpkins and butternuts struggle through July and August here, while cushaw vines through 100°F afternoons and red-clay subsoil and still set 4–8 marketable fruit per plant. The crop has historic depth in the Ozarks and Cross Timbers as a "hog squash" (cooked and fed to livestock) as well as a pie and sweet-bread squash. Cushaw does not naturalize as a weed; it requires cultivated soil and dies at the first hard frost. It will, however, cross-pollinate readily with other C. argyrosperma varieties at distances up to a half mile, so seed savers must isolate or hand-pollinate.

Ecology & Wildlife Value

[ squash bees · vine borer ecology · three sisters · seed dispersal ]

Squash bees — the obligate pollinator

The eastern squash bee (Peponapis pruinosa) is a ground-nesting solitary native bee whose entire reproductive cycle is tied to the genus Cucurbita. Females forage cushaw and pumpkin flowers in the cool of dawn (peak flight 5:30–9:00 a.m. in Tulsa summers), pollinate them efficiently, then sleep inside closed male flowers through the heat of the day. A backyard cushaw planting next to undisturbed soil can establish a persistent local population of squash bees that pollinate every cucurbit in the neighborhood for years.

Vine-borer resistance

Squash vine borer (Melittia cucurbitae) is the single worst pest of C. pepo across NE Oklahoma — many gardeners give up on zucchini and yellow squash by mid-July because of it. Cushaw, in contrast, is significantly more resistant: its tough, often hollow main stem and the species' habit of rooting at every node make individual borer attacks far less destructive. A cushaw plant with one or two boreed stems usually keeps producing from rooted lateral vines.

Three-sisters polyculture

Cushaw is the canonical southern-Plains "squash" partner in the three-sisters interplant with maize and beans/cowpeas. The big squash leaves shade the soil and suppress weeds; the corn provides a living trellis (cushaw vines twine modestly upward along the stalks); the legume fixes nitrogen for both. Documented in Indigenous gardens of eastern Oklahoma since pre-contact and revived in many heritage-seed and food-sovereignty projects today.

Wildlife & pests

Beyond squash bees, flowers attract bumblebees, halictid sweat bees and honey bees. Striped and spotted cucumber beetles feed on foliage and transmit bacterial wilt (Erwinia tracheiphila) — cushaw is less affected than C. pepo, but still vulnerable. Raccoons, deer and feral hogs strip mature fruit; a fence helps in rural plantings.

The squash-bee conservation case for cushaw: Where many home gardeners apply broad-spectrum insecticides to their cucurbits to chase squash bug and vine borer, cushaw lets you grow squash through August with very little spraying — preserving the squash-bee population that pollinates everyone's cucurbits. If you are growing any cucurbit in Tulsa and want to do right by the native bees, plant cushaw and skip the routine sprays.

Seed-saving isolation: Cushaw will cross with other C. argyrosperma cultivars within roughly a half mile by squash-bee flight, but will not cross with zucchini/pumpkin (C. pepo), butternut (C. moschata) or banana squash (C. maxima). To save true-to-type seed in a NE Oklahoma neighborhood with other gardens, hand-pollinate and tape closed female flowers, or grow only one cushaw cultivar at a time.

Horticulture & Care

[ sowing · spacing · heat management · harvest · cure · storage ]

When to plant

Cushaw needs warm soil and a long warm season. In Tulsa, direct-sow seed after May 1, when soil at 2 in is steadily above 65°F. A single planting carries through the season — cushaw is a long-season crop and does not need succession sowing. For three-sisters, sow corn first, wait two weeks for stalks to reach knee-high, then sow cushaw and cowpea/beans together at the base of the corn.

Planting & establishment

Soil: deep loam with 2–4 in of compost incorporated; pH 6.0–7.0; the heaviest feeder of the cucurbits but tolerant of red clay if amended.
Sowing: 1–1.5 in deep, 4–5 seeds per hill, then thin to the strongest 2 plants per hill.
Spacing: hills 6–8 ft apart in rows 8–10 ft apart; or single plants in three-sisters mounds 4–5 ft apart.
Water: deep weekly soakings of 1 in; mulch heavily after seedlings reach 6 in to conserve moisture and keep fruit clean.
Mulch: 3–4 in straw or grass clipping mulch; cool soil extends summer productivity.
Fertilizer: a side-dress of compost or fish emulsion at first bloom; do not over-fertilize with nitrogen (more leaves, fewer fruit).

In-season management & pruning

Train vines along a path or fence edge if space is tight; tip-prune to limit a vine to 12–15 ft when it threatens neighboring crops. Bury vines lightly at nodes to encourage adventitious roots — this is the cushaw gardener's main insurance against vine borer. Remove and burn (do not compost) any obviously borer- infested stem section — cut with a clean knife and dig out the larva.

Harvest & cure

Harvest: when the rind is hard enough to resist a thumbnail and the stem is dry and corky; typically late September through October in Tulsa. Cut with 2–3 in of stem attached — a broken stem invites rot.
Cure: 1–2 weeks in a warm dry place (75–85°F) to heal small cuts and harden the rind. A covered porch is ideal.
Store: single layer in a cool dry pantry (50–70°F); expect 3–6 months of good eating quality, longest in the smaller fruit.
Seed save: select fully ripe fruit from your best plants; scoop seeds, rinse off pulp, dry on a screen for 1–2 weeks, store in airtight jars. Viability 5–7 years.

Pests & diseases

Squash vine borer — cushaw is its most resistant cucurbit; bury vines at nodes for insurance.
Squash bug (Anasa tristis) — can build dense colonies under leaves and on fruit. Hand-crush egg clusters (orange, in geometric arrangements on leaf undersides); knock adults into soapy water.
Cucumber beetles — transmit bacterial wilt; floating row cover until first bloom, then remove for pollinators.
Powdery mildew — cosmetic late-season; ensure airflow.
Anthracnose & downy mildew — rare in NE Oklahoma's dry summers; rotate cucurbits on a 3–4 year cycle.

Notable heirloom varieties for NE Oklahoma

Variety	Fruit	Distinguishing feature	Notes for Tulsa
'Tennessee Sweet Potato'	Pear-shaped, 10–15 lb, cream with green stripes	Sweetest cushaw; classic for pies and sweet bread	Excellent NE OK pie squash; flesh dries down sweet and rich. The heirloom most often listed in Southern seed catalogs.
'Green-Striped Cushaw'	Crookneck, 10–20 lb, cream with deep green stripes	Most distinctive look; very productive	The classic three-sisters squash of the southern Plains; tough vines, heavy yields, mild flesh. Documented Choctaw and Cherokee variety.
'White Cushaw' / 'Jonathan Pumpkin'	Crookneck, 8–15 lb, solid ivory-white	Pure white rind; mild buff flesh	Beautiful color contrast in the garden; ideal for fall display and long storage.
'Hopi Cushaw' / 'Hopi Striped'	Crookneck, 8–12 lb, blue-gray with white stripes	Drought-tough Hopi heirloom	Best for low-water gardens; sweet flesh, attractive fruit, good keeper.
'Magdalena Big Cheese'	Round-cheese, 15–25 lb, tan-orange	Pueblo heirloom from New Mexico; very large flat fruit	Heavy producer; dual-purpose seed and flesh; shape unusual for cushaw.
'Cochiti Pueblo'	Crookneck, 10–15 lb, mottled green	Indigenous Southwestern heirloom; vigorous and heat-loving	Premier choice for hot dry NE OK summers; long-storing.

Cultural & Material Uses

Cushaw is one of the deeper culinary and agricultural threads connecting NE Oklahoma's Indigenous, African American, settler and Mexican-American foodways — a single crop that carried through forced removals, hard winters, and the Dust Bowl, and is currently being restored in heritage-seed projects across the southern Plains.

Cushaw pie & sweet bread: The classic Southern dessert use. Tennessee Sweet Potato flesh roasts down to a thick, mild sweet purée that goes into pumpkin pie, sweet bread, custards and quick breads. Mild enough that some heirloom NE OK pie recipes specify cushaw rather than pumpkin.
Three-sisters polyculture: Documented in the gardens of the Caddo, Wichita, Cherokee, Choctaw and Creek peoples in present-day Oklahoma, with cushaw as the standard squash partner alongside maize and beans/cowpeas. The interplant predates the Indian Removals (1830s) by centuries.
Calabaza en tacha & Mexican confitada: Cushaw is a primary squash for the Mexican holiday confection calabaza en tacha — slabs of squash slow-cooked with piloncillo, cinnamon and orange. This use travels into the Tex-Mex and Oklahoma-Mexican kitchens of the region.
Pepitas: The large flat silvery seeds are some of the best cucurbit seeds for roasting. Cushaw seed has high oil content and a nutty flavor — toast lightly with salt or chile.
Hog squash & livestock feed: Cushaw is a traditional NE OK and Ozark fall livestock feed; whole or chopped fruit, sometimes cooked, is fed to pigs, cattle and chickens. The high yield and tough rind make it ideal for storage feed.
Squash blossoms: Male flowers, picked in early morning, are edible — battered and fried as quesadillas de flor de calabaza. Pick excess males to avoid reducing fruit set.
Heritage seed networks: Cushaw is championed by Southern Exposure Seed Exchange, Native Seeds/SEARCH (Tucson), and the Cherokee Nation Seed Bank in Tahlequah, OK, all of which steward multiple regional landrace strains.

Sources & Further Reading

USDA NRCS PLANTS Database — Cucurbita argyrosperma: plants.usda.gov/plant-profile/CUAR8
Oklahoma State University Extension — Squash and Pumpkin Production in Oklahoma (HLA-6027), with specific notes on vine-borer-resistant cushaw types.
Cherokee Nation Seed Bank, Tahlequah, OK — heirloom C. argyrosperma stewardship and member-distribution program.
Native Seeds/SEARCH (Tucson, AZ) — cushaw landrace catalog and cultural notes for southern Plains and Southwest Indigenous communities.
Southern Exposure Seed Exchange — cushaw variety catalog and Southern-foodways grower notes.
Lady Bird Johnson Wildflower Center — Cucurbita argyrosperma plant database entry.
Wikipedia — Cucurbita argyrosperma: en.wikipedia.org/wiki/Cucurbita_argyrosperma (CC BY-SA 4.0).
Hurd, P.D., Linsley, E.G. & Whitaker, T.W. (1971), "Squash and gourd bees (Peponapis, Xenoglossa) and the origin of the cultivated Cucurbita", Evolution 25: 218–234.
Mt. Pleasant, J. (2006), "The science behind the Three Sisters mound system: an agronomic assessment of an Indigenous agricultural system in the northeast", in Histories of Maize, Academic Press — relevant to southern-Plains cushaw use as well.

Photos courtesy of Wikimedia Commons contributors under their respective licenses.

Cushaw Squash

Identification

Vine & stem

Foliage

Flowers

Fruit, seed & lookalikes

Habitat & Range in NE Oklahoma

Ecology & Wildlife Value

Squash bees — the obligate pollinator

Vine-borer resistance

Three-sisters polyculture

Wildlife & pests

Horticulture & Care

When to plant

Planting & establishment

In-season management & pruning

Harvest & cure

Pests & diseases

Notable heirloom varieties for NE Oklahoma

Cultural & Material Uses

Sources & Further Reading

Companion Planting