Wait for warmth to plant winter squash.

Winter squash is a warm-season vegetable that can be grown in most of the country. It differs from summer squash in that it is harvested and eaten in the mature fruit stage when the seeds within have matured fully and the skin has hardened into a tough rind. When ripened to this stage, fruits of most varieties can be stored for use throughout the winter.

Types of Winter Squash

Winter squash are adapted to a wide variety of conditions. They are vining types unless otherwise indicated. Vining squash plants require considerable growing space and are best suited for large gardens. The bush and semi-vining types can be grown in smaller gardens. Occasionally, some of these varieties may be listed as pumpkins by certain seed companies. The distinction between squash and pumpkins is mainly in what you choose to call them.

• Acorn (C. Pepo)—80 to 100 days to harvest.
• Delicata (C. Pepo)
• Spaghetti (C. Pepo)
• Butternut (C. Mopschata)
• True Winter Squash (C. Maxima)

For giant varieties, see pumpkin.

Growing Winter Squash

When to Plant

Squash is a tender vegetable. The seeds do not germinate in cold soil, and the seedlings are injured by frost. Do not plant until all danger of frost is past and the soil is thoroughly warmed.

Spacing & Depth

The vining types of squash require at least 50 to 100 square feet per hill.

• Plant seeds one inch deep (four or five seeds per hill).
• Allow 5 to 6 feet between hills.
• When the young plants are well-established, thin each hill to the best two or three plants.
• Allow 7 to 12 feet between rows.
   

Plant semi-vining varieties one inch deep (four or five seeds per hill) and thin to the best two plants per hill. Allow 8 feet between rows.

Plant bush varieties one inch deep (1 or 2 seeds per foot of row) and thin to a single plant every three feet. Allow five feet between rows.

Care

Squash plants should be kept free from weeds by hoeing and shallow cultivation. Irrigate if an extended dry period occurs in early summer. Squash requires minimal care after the vines cover the ground.

Bees are necessary for pollinating squash and pumpkins but are killed by insecticides. If insecticides are used, they should be applied in the late afternoon or early evening after the bees stop visiting blossoms for the day and avoid spraying the flowers where some bees will spend the night

Common Problems

Cucumber beetles attack seedlings, vines, and both immature and mature fruits. They can be controlled with a suggested insecticide applied weekly either as a spray or dust. Be alert for an infestation of cucumber beetles in early September because these beetles can damage the mature fruits.

Squash bugs attack vines as the fruit begin to set and increase in numbers through the late summer when they can be quite damaging to maturing fruit. They hatch and travel in groups, which seem to travel in herds until they reach maturity. Using the proper insecticide when the numbers of this pest are still small minimizes damage.

Squash vine borer will cause a plant to wilt seemly overnight. The adult is a beautiful clear-winged moth. It flies during the daytime and lays eggs singly at the base of the squash plants or on leaf petioles.

• The egg hatches in 7-10 days and the larva bore into the stem of the plant leaving a trail of waste behind where it feeds on the stem tissues.
• The damaged stem tissues cannot facilitate translocation of water and nutrients. This causes the vine to wilt and the whole plant may eventually die.
• The infestation is more serious during the extended dry period in early summer.
• Squash that still vine can be kept alive by rooting the stem every foot or so along the vine.
• The squash vine borer overwinters as a pupa in the soil near the former squash plant and appears again in mid-June to July the following year.

Like many animals, some insects have their preference of food.

• Blue Hubbard squash is a preferred meal for squash bugs and squash vine borer and can be used as a trap crop.
• Plant blue Hubbard squash at the ends of the row or garden corners to attract squash bugs and squash vine borer.
• The trap will need to be treated with an insecticide but will spare having to spray much of the other squash in the garden.
   

Harvesting Winter Squash

Winter squash can be harvested whenever the fruits have turned a deep, solid color and the rind is hard. Harvest the main part of the crop in September or October, before heavy frosts hit your area. Cut squash from the vines carefully, leaving two inches of stem attached if possible. Avoid cuts and bruises when handling. Fruits that are not fully mature, have been injured, have had their stems knocked off, or have been subjected to heavy frost do not keep and should be used as soon as possible or be composted (watch for seedlings in the compost).

Store in a dry building where the temperature is between 50 and 55°F. For prolonged storage, do not pile squash more than two fruits deep. It is preferable, where space allows, to place the fruits in a single layer so that they do not touch each other. This arrangement minimizes the potential spread of rots.

Selection & Storage

The squash family (Cucurbitaceae) includes pumpkins, summer squash, and winter squash. They are really edible gourds. There are many varieties with a wide range of flavors and textures. Winter squash does not look the same either. Their tough outer shells can be smooth or bumpy, thin or thick, and rock hard with a wide array of colors.

The most popular winter squash includes acorn, buttercup, butternut, calabaza, delicata, Hubbard, spaghetti, sweet dumpling, and Turk's Turban. There are many more, but this section will be limited to the above-mentioned varieties.

Winter squash is planted in the spring, grows all summer, and is always harvested at the mature stage in early autumn before the first frost. Immature winter squash lacks flavor, so wait until the rind is hard. Harvest winter squash with two inches of stem remaining. A stem cut too short is like an open wound, which will cause early decay.

For storage, harvest sturdy, heavy squashes with fairly glossy skin that is unblemished by soft spots, cuts, breaks, or uncharacteristic discoloration. Most winter squash benefits from a curing stage; the exceptions are acorn, sweet dumpling, and delicata. Curing is simply holding the squash at room temperature (about 70 degrees) for 10 to 20 days.

After curing, transfer to a cool (45 to 50 degrees), dry place such as the basement or garage for long-term storage. Be careful, do not allow them to freeze. The large hard rind winter squash can be stored for up to six months under these conditions. Warmer temperatures simply mean shorter storage time.

The smaller acorn and butternut do not store as well, only up to 3 months. Store cut pieces of winter squash in the refrigerator. Refrigeration is too humid for whole squash, and they will deteriorate quickly.

Questions and Answers

Q. Can squash varieties cross-pollinate with one another or with pumpkins in the garden?

A. Yes. Any variety of squash or pumpkin in the same species can cross-pollinate. Cross-pollination does not affect the current crop, but the seed does not come true the following year.

Q. Does squash make as good a pie as pumpkin?

A. Yes. Most people cannot tell whether pumpkin or squash is used in a pie. This finding is not surprising given the whimsical application of the names pumpkin and squash. Many cooks prefer winter squash to pumpkin because they make a non-fibrous pie, much more akin to the C. moschata processing pumpkins commonly bought canned. (C. moschata is closely related to butternut squash.)

Q. I have vine borers in my squash. Can I control them with insecticides?

A. No. Vine borers cannot be controlled effectively with insecticides. You can reduce potential damage the following season by disposing of infested plants. Vining types of squash can be encouraged to root at the nodes, giving the plant some ability to withstand attacks of vine borers. Some success in control of an active infestation may be achieved by carefully splitting open areas being fed upon and removing the larvae.

Q. Is Turk's Turban an edible squash?

A. Yes, but it has relatively poor flesh quality and is more often grown for its ornamental value than for cooking.