What hardiness zones is Cucurbita maxima 'Buttercup' suitable for?

Cucurbita maxima 'Buttercup' is an annual vine reaching 15-18 inches (38-45 cm) tall with a spread of 6-10 feet (1.8-3 m) and a trailing, vining habit. Developed by North Dakota Agricultural Experiment Station in 1925, it produces drum-shaped (turban-type) fruits 6-8 inches (15-20 cm) in diameter weighing 3-5 pounds (1.4-2.3 kg) with a distinctive button or cup-shaped protrusion on the blossom end. Dark green rind with grey-green striping. Thick, golden-orange, dense, dry, sweet flesh—among the driest and sweetest of winter squashes, with a chestnut-like flavor. Days to maturity 90-100 from transplant. Growth rate is fast. Stores 3-4 months. Frequently confused with kabocha (also C. maxima) but buttercup has the distinctive blossom-end button.

Native Range

Cucurbita maxima originated in South America—Andes region. 'Buttercup' was developed at North Dakota Agricultural Experiment Station in 1925.

Suggested Uses

Grown in vegetable gardens for culinary use—roasting, mashing, soups, pies. Driest sweetest winter squash—chestnut-like flavor. 3-5 lb personal/family size. Stores 3-4 months. ND 1925 heirloom. Blossom-end button fragile—handle carefully. Requires 6-10 ft vine spread. Not suitable for small gardens without trellising.

How to Identify

Distinguished from 'Blue Hubbard' by the much smaller size (3-5 versus 12-20 lb), the drum/turban shape (versus teardrop), and the dark green (versus blue-grey) rind. Distinguished from butternut (C. moschata) by the drum shape (versus bell shape), the button on blossom end, and the C. maxima (versus C. moschata) species. Distinguished from kabocha by the blossom-end button and the grey-green striping. Buttercup—drum-shaped with button, dark green, driest sweetest flesh, chestnut flavor, ND 1925.

Appearance

Size & Dimensions

Height1'3" - 1'6"

Width/Spread6' - 10'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Summer

Large yellow-orange flowers—male first, then female. Bee pollination essential. Each vine produces 3-5 fruits.

Detailed Descriptions

Flower Description

Yellow-orange; large; male and female separate; bee-pollinated

Foliage Description

Dark green; large rounded; on trailing vines

Growing Conditions

Sun Requirements

Full Sun

Requires 8-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.0(Neutral)

357912

Soil Types

loam

Drainagewell drained

Water & Climate

Water Needs

High

Frost Tolerance

tender

Time to Maturity

90-100 days from transplant

Care & Maintenance

Care Guide

Start seed indoors 3-4 weeks before last frost, or direct sow after soil warms to 70°F (21°C). Full sun, well-drained, fertile soil (pH 6.0-7.0). Hills with composted manure. Heavy feeder. Days to maturity 90-100 from transplant. Handle carefully—the blossom-end button is fragile and damage there shortens storage life. Cure 1-2 weeks in warm dry location. Stores 3-4 months at 50-55°F (10-13°C).