All About Growing Winter Squash

Buttercup squash rival butternuts in flavor and productivity. The vigorous plants produce heavy crops of squat, green fruits. Fruits will store for four to six months.

Hubbard squash and kabocha squash range from medium-sized to huge and have drier flesh than other winter squash. Rind color varies with variety, and all varieties will store for four to six months. (Hubbard squash are so attractive to squash vine borers that some gardeners use this type as a “trap crop” for this insect pest.)

Cylinder-shaped delicata squash and pumpkin-shaped dumpling squash produce single-serving-size, ivory fruits with green stripes that turn orange in storage. Fast to mature, these are among the easiest winter squash to grow in cool climates. Fruits will store for three to five months.

Acorn squash are ribbed, round fruits that have gold or green rinds. They mature quickly and will store for at least three months, making them popular in areas with short summers.

Spaghetti squash are full of stringy fibers that resemble pasta. The oblong fruits have smooth rinds that range from tan to orange, and they will store for three to six months.

Cushaw squash produce big, bulb-shaped fruits with dense, sweet flesh. Plants need a long, warm growing season and will store for at least four months.

See our chart of winter squash species for more information to help you find the perfect winter squash for you.

When to Plant Winter Squash

In spring, sow seeds in prepared beds or hills after your last frost has passed, or sow them indoors under bright fluorescent lights. Set out seedlings when they are about three weeks old. In Zone 6 and warmer, you can plant more winter squash in early summer, using space vacated by fall-planted garlic or early spring lettuce. Stop planting winter squash 14 weeks before your expected first fall frost.

How to Plant Winter Squash

Winter squash grows best in warm conditions, in fertile, well-drained soil with a pH between 6.0 and 6.5. Choose a sunny site and prepare 3-foot-wide planting hills within wide rows, or position them along your garden’s edge. Leave 5 to 6 feet between hills. Loosen the soil in the planting sites to at least 12 inches deep. Thoroughly mix in a 2-inch layer of mature compost and a light application of balanced, organic fertilizer. Water well. Plant six seeds per hill, poking them into the soil 1 inch deep. After seeds germinate (about 10 days after sowing), thin seedlings to three per hill. Set up protective row covers as soon as you’re done planting. (See The No-Spray Way to Protect Plants for more information on how to guard your garden crops with row covers.)

Harvesting and Storage

Fruits are ripe if you cannot easily pierce the rind with your fingernail. Never rush to harvest winter squash, though, because immature fruits won’t store well. Unless pests or freezing weather threaten them, allow fruits to ripen until the vines begin to die back. Expect to harvest three to five squash per plant. Use pruning shears to cut fruits from the vine, leaving 1 inch of stem attached. Clean away dirt with a soft, damp cloth, and allow fruits to cure for two weeks in a spot that’s 70 to 80 degrees Fahrenheit. Store cured squash in a cool, dry place, such as your basement, a cool closet or even under your bed. Check every two weeks for signs of spoilage.

Saving Seeds

If you harvest your winter squash after the fruits have fully matured, saving seeds is simply a matter of rinsing, drying and storing the biggest, plumpest seeds that come across your cutting board. If stored in a cool, dry place, winter squash seeds remain viable for up to six years. Be sure to isolate varieties of the same species by planting them at opposite ends of the garden, or by growing one variety early in the season and another from midsummer to fall. Also keep in mind that acorn, delicata, dumpling and spaghetti squash can cross with summer squash, which is of the same species (Cucurbita pepo).

Preventing Winter Squash Pests and Diseases

Winter squash face challenges from squash bugs, squash vine borers, and cucumber beetles. To defend your plants from all three insects, shield them with row covers held aloft with stakes or hoops until the plants begin to bloom. Big, healthy plants will produce well despite pest pressure. Among diseases, powdery mildew is a common problem best prevented by growing resistant varieties, which often have “PMR” (for “powdery mildew resistance”) after their variety names. In addition, a spray made of 1 part milk and 6 parts water can suppress powdery mildew if applied every two weeks during the second half of summer. To see other readers’ squash bug prevention tips and post your own — and for instructions on how to make Mother’s own squash bug squisher — check out Homemade Squisher for Squash Bug Control.

Winter Squash Growing Tips and Ideas

Grow open-pollinated varieties so you can save your own seeds for eating and replanting. Only choose hybrids if you need a space-saving bush habit or a special form of disease resistance.

Try growing winter squash in an old compost pile located along the edge of your garden. Small-fruited varieties do well if allowed to scramble up a fence.

Cooking With Winter Squash

Old-fashioned squash pies laced with cinnamon and ginger will never go out of style, but newer trends in winter squash cuisine favor savory risottos and creamy, squash-stuffed ravioli. Sage is a great accent herb for winter squash, and some cooks brush maple syrup or honey onto chunks of baked (or grilled) squash to create a caramel glaze. Make large fruits easier to cut by lopping off a slice from one side using a sharp, heavy knife, creating a flat surface. Cut large fruits into chunks before removing the rinds. Winter squash seeds are also edible and delicious! Roast the rinsed, dried seeds at 275 degrees Fahrenheit until they just begin to pop, about 15 to 20 minutes. Season with sea salt and enjoy.

Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.