Buttercup winter squash with decorative carving on a white background
One cut and one whole Buttercup Winter Squash in wooden box on metal background.
Buttercup winter squash with decorative carving on a white background
One cut and one whole Buttercup Winter Squash in wooden box on metal background.

Winter Squash Seeds,
Buttercup

4.319 Reviews#SQ110 · 20 seeds
Price
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Description

(Cucurbita maxima). The satiny soft texture and unmistakable chestnut flavor of this turban squash is reminiscent of the famous ancient Japanese-bred kabochas. In reality, this exceptional variety was bred at North Dakota State University in the 1920s as a replacement for sweet potatoes. Northern researchers found a chance cross between the Essex and Quality varieties, and they named their happy accident Buttercup. The rugged plants thrived in the notoriously brief N.D. growing season. The researchers also appreciated its early maturity and natural insect resistance and conducted exhaustive taste tests. Selection resulted in the dusty aquamarine-colored fruit of perfect family serving size with bright orange flesh, exceptional mild sweet flavor, and creamy texture. University of North Dakota researchers exclaimed “Each squash weighs 3- 3.5 pounds, just enough to serve 5 to 6 people in one meal with no leftovers." The nutritious starchy flesh made a perfect substitute for those northern growers yearning for the elusive semi-tropical sweet potatoes of the South. A shining example of pre-industrialized breeding, where flavor and texture were considered equally important as yield and vigor.

Plant Details

Botanical Name
Cucurbita maxima
Life Cycle
Annual
Growth Habit
Vining
Sun Requirement
Full sun
Days to Germinate
7–12
Days to Maturity
90–100
Planting Depth
1 in.
Plant Spacing
36–48 in.
Ideal Temperature
70–95°F
Frost Hardy
No

Growing Guide

When to Grow

Start Buttercup squash seeds indoors 3–4 weeks before your last expected frost, or direct sow after all danger of frost has passed and soil temperatures are at least 65°F. In warm climates, a second planting can be made in midsummer for a late fall harvest. If you’re not sure how to find your first and last frost dates, consult our blog post 'Our Experts Answer Questions, Share Resources.'

How to Sow and Plant

Plant seeds 1 inch deep in fertile, loose soil enriched with compost or well-rotted manure. Buttercup squash needs space to spread, so sow seeds 36–48 inches apart in rows or mounds. Water thoroughly after planting and maintain consistent moisture during germination to encourage strong, healthy sprouts.

How to Grow

After seedlings appear, thin to the strongest plants. Support sprawling vines with ample space or train them onto a sturdy trellis to save garden room. Regularly check for pests and diseases, and apply organic remedies as needed. Deep, infrequent watering encourages deep root growth. Harvest Buttercup squash when rinds are hard and skin color is deep and uniform.

How to Save Seeds

  • There are four different species of squash: Cucurbita maxima, C. pepo, C. moschata, and C. mixta. They will not cross pollinate with each other, so it is possible to grow one of each species for seed saving without worrying about cross pollination.
  • If you are planning to grow several varieties of more than one species, you can bag the blossoms and hand pollinate to avoid crossing.
  • Whether it is a summer or winter squash, you must let the fruit completely mature before extracting the seeds, and cure for at least two weeks.
  • Scoop the seeds, place them in a bucket, and add just enough water to cover. Let sit at room temperature to ferment for two days before rinsing off the pulp.
  • Lay seeds out to dry on newspaper or paper plates.
  • Stored in a cool, dry place, seeds will remain viable for up to four years

FAQ

How long does it take for Buttercup squash seeds to germinate?

Buttercup squash seeds typically germinate in about 7 to 12 days when soil temperatures are consistently between 70°F and 85°F. Warmer soils will speed up the process slightly.

Can Buttercup squash be grown in containers?

Yes, Buttercup squash can grow in very large containers (at least 20 gallons) with a sturdy trellis to support the vines. Choose dwarf varieties if space is extremely limited.

Do I need to hand-pollinate Buttercup squash?

In many gardens, natural pollinators like bees will do the job. However, if you notice poor fruit set, you can hand-pollinate by transferring pollen from male to female flowers using a small paintbrush.

Browse our full range of winter squash seeds.

Customer reviews

4.3 / 5 19 Reviews

What gardeners are saying

  • Sweet, dry, nutty: Dense, non-stringy flesh like sweet potato; roasts or mashes well.

  • Personal-sized fruit: Most squash run two to three pounds, enough for one or two.

  • Tough, trouble-free vine: Shrugs off heat, drought and mildew; bugs mostly leave it alone.

  • Prolific grower: Up to a dozen or more fruit per vine; give it plenty of room.

  • Heads up: Not a long keeper; eat within a month or two of harvest.

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