How to grow winter squash and store it all winter

Winter squash grows all summer and stores for months after harvest. Butternut, acorn, spaghetti, delicata, kabocha, and hubbard squash are all winter squash. So are pumpkins.

They are called winter squash because they keep into winter, not because they grow then. With a little care at harvest, you can eat your own squash until spring.

When to plant winter squash

Winter squash is a warm-season crop. Sow seeds outdoors after your last spring frost, once the soil is at least 65°F (18°C). Seeds rot in cold, wet soil.

Most varieties need 80 to 110 days to mature. In short-season areas, start seeds indoors 3 to 4 weeks before your last frost. Use pots you can plant whole, since squash does not like its roots disturbed.

Where to plant winter squash

• Full sun, at least 8 hours a day
• Rich, well-drained soil with lots of compost
• Plenty of room, since most vines spread 10 to 15 feet (3 to 4.5 m)

Short on space? Grow bush varieties, or train vines up a sturdy trellis. Smaller squash like acorn and delicata climb well.

How to plant winter squash

1. Work 2 to 3 inches (5 to 8 cm) of compost into the bed.
2. Sow 2 or 3 seeds 1 inch (2.5 cm) deep in a group.
3. Space groups 3 to 4 feet (1 to 1.2 m) apart, in rows 6 to 8 feet (2 to 2.5 m) apart.
4. Once seedlings have true leaves, thin to the strongest plant in each group.
5. Water well, and mulch once the soil is warm.

Water and feeding

Squash plants are big and hungry. Give them about 1 inch (2.5 cm) of water a week, more in hot weather. Water at the base of the plant, not over the leaves, to help prevent powdery mildew.

Side-dress with compost when the vines start to run, and again when the first fruit forms.

Flowers and pollination

Squash plants have male and female flowers. The male flowers open first and drop off. That is normal. Female flowers have a tiny squash at the base.

Bees carry pollen from male to female flowers. If small squash turn yellow and fall off, they were not pollinated. You can hand-pollinate. Pick a male flower, peel back the petals, and brush the pollen onto the center of an open female flower in the morning.

How to tell when winter squash is ready

Leave squash on the vine until it is mature. Check for these signs:

• The skin is hard and you cannot dent it with a fingernail.
• The color is deep and even for the variety.
• The stem near the fruit is turning dry and corky.
• The spot where the squash sat on the ground has turned cream, yellow, or orange.

Harvest before a hard frost. Light frost on the leaves is fine, but frost on the fruit shortens its storage life.

Cut squash from the vine with pruners, leaving 1 to 2 inches (2.5 to 5 cm) of stem. Do not carry squash by the stem. A broken stem lets rot in.

How to cure winter squash

Curing toughens the skin and helps squash store longer. Most winter squash taste sweeter after curing too.

1. Wipe off any soil.
2. Set the squash in a warm, dry spot for 10 to 14 days. Aim for 80 to 85°F (27 to 29°C).
3. A sunny porch, greenhouse, or warm room works.

Do not cure acorn squash. It stores best when it goes straight into cool storage.

How to store winter squash

Store cured squash in a cool, dry place, around 50 to 55°F (10 to 13°C). A cool basement, closet, or spare room works. Do not store them in the fridge or anywhere that freezes. Keep them in a single layer so they do not touch, and check them every few weeks.

Squash	How long it stores
Hubbard	Up to 6 months
Butternut	3 to 6 months
Kabocha	3 to 5 months
Spaghetti	1 to 2 months
Acorn and delicata	1 to 2 months

Eat the ones with nicks or soft spots first.

Common winter squash problems

• Squash bugs suck sap from leaves and vines. Here is how to get rid of squash bugs.
• Powdery mildew coats leaves in late summer. Here is how to get rid of powdery mildew.
• Small fruit that rots or falls off was not pollinated. Hand-pollinate in the morning.
• Lots of vines and few squash can mean too much nitrogen. Use compost instead of high-nitrogen fertilizer.

More squash family posts

• How to grow pumpkins
• Pumpkin species
• How to save squash seeds
• How to grow sweet corn, a classic partner for squash