UC Master Gardeners, Santa Clara County, CA
University of California
UC Master Gardeners, Santa Clara County, CA

Winter Squash (including pumpkins)

Despite its name, winter squash is grown in the summer. The name comes from the fact that the mature fruits can be stored for winter eating, unlike summer squashes such as zucchini which are harvested young and eaten immediately. Pumpkins are also types of winter squash.

UC Links
winter squash K 2006

How to grow: Winter Squash

Pest management: Squash cultural tips, pests, and diseases

The Basics

When to plant: May–June. For best results, wait until soil is well warmed up in the spring. Plant directly from seed or from transplants.

Harvest window: September–November, depending on variety

Care overview:

  • Encourage bees for best pollination.
  • Train vining squash plants on trellises or cages to conserve space in your garden, or let ramble over non-garden surfaces. Bush varieties are more compact.
  • Treat squash bugs aggressively if found on plants.

Harvesting and storage:

  • Mature winter squash have a hard outer shell and a well corked stem.
  • Immature fruit have a tender skin and a fleshy stem. They won't keep in storage but can be used like summer squash.
  • Any injury to the rind can be a site for decay, including if the stem has broken off, so use damaged squash first.
  • Winter squash are best stored at 55-59°F and can last 2 to 6 months depending on the variety. Cucurbita pepo types such as acorn, spaghetti, and delicata are best eaten in the fall. Cucurbita maxima types such as hubbard, buttercup, and kabocha squash are best eaten in December/January; their sweetness will actually increase during storage. Cucurbita moschata types such as butternut will store the longest.

Some Recommended Varieties for Santa Clara County*

Variety NameDescription
Blue Ballet Smaller version of Blue Hubbard, averaging 4–6 lbs. Rind is blue-gray, bright orange flesh is sweet and smooth. Skin is more tender than other hubbards. C. maxima
Buttercup Small, dense fruits average 3 lbs. Skin is dark green skin with pale green stripes. Orange flesh is sweet, rich and dry. C. maxima
Butternut Small fruits average 3–6 lbs. Skin is a uniform tan. Golden flesh is nutty and sweet. Some resistance to squash bugs. C. moschata
Delicata Little oblong fruits average 1 1/2 to 2 lbs. Skin is creamy white with dark green stripes. Golden flesh is sweet and smooth. C. pepo
Stella Blue Small flattened round fruits are 2–6 lbs. Skin is slate blue. Deep orange flesh is sweet, dry, and flaky. C. maxima
Sweet Dumpling Tiny round fruits average just 1 lb. Skin is creamy white with dark green rib stripes. Orange flesh is tender and sweet. C. pepo
Tahitian Large fruits average 8–30 lbs and look like a giant butternut squash. Flesh is unusually sweet. Some resistance to squash bugs. C. moschata

* Many other varieties may also do well here in Santa Clara County. This list is based on UC Master Gardener trials, taste tests, and feedback from local growers.

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