Family: Cucurbitaceae
Genus and Species: Cucurbita pepo

Climate

Winter squash needs 3 months of warm, frost free conditions to produce fruit. Winter squash plants are frost sensitive. Winter squash fruits will tolerate a light frost.

Soil

Winter squash needs fertile, aerated soil that is warm enough for germination (70°-90°) and warm enough for growing (65°-75°). Winter squash takes well to soil amended with compost or well-rotted manure. Winter squash grows best in soils with a pH between 5.5 and 6.5. Winter sqash needs moderate amounts of potassium and phosphorus and high amounts of nitrogen.

Spacing

Grow winter squash in a corner of the garden and train the vines to grow outside of the garden. Give winter squash about 2' apart in rows that are 2' apart.

Winter squash can also be grown in soil hills. To plant winter squash in hills, set one plant per hill and space the hills 4'-5' apart. Make the hills by mounding topsoil, compost, and well-rotted manure. Winter squash is a heavy feeder and when grown in these hills are more likely to get what they need.

Direct Seeding

Direct seed winter squash once the danger of frost is past and soil temperatures are between 70° and 90°. Use black plastic to warm the soil if needed.

Seeding For Transplants

Winter squash seeds can be started indoors one month before the last frost. Sow winter squash seeds in peat pots or cell trays 1/2" deep. Place the pot or cell trays under grow lights. Sow winter squash seeds 3 per pot/cell then thin to one squash plant once squash seedlings are established.

Germination

These seeds germinate best in soils around 70°F-90°F.
Germination will take 6-10 days.

Transplanting Into the Garden

Transplant winter squash starts when the soil is 70°-90°. Use black plastic to warm the soil. If using peat pots, slit the pots and place them into moist, warm soil. Water thoroughly.

Watering

Winter squash need to be watered throughout the growing season. Keep winter squash evenly moist and water deeply during dry spells. Water the bases of the winter squash plants to prevent mildew. Don't water the foliage. Watering winter squash in the early morning also helps prevent mildew. Winter squash also needs a lot of nutrients. Winter squash plants benefit from a monthly application of a complete organic fertilizer like fish emulsion or seaweed.

Harvesting

Winter squash are mature when the stems connecting the fruit to the vine begin to shrivel.

Cut the winter squash from the vine rather than snapping it free. Cut winter squash from the vines carefully, leaving two inches of stem attached if possible.

Post-Harvest Handling

Wash and dry winter squash thoroughly. Avoid cuts and bruises when handling. To ensure long storage life for winter squash the fruit must be cured and stored properly. Immature fruit are poor quality and cannot be successfully stored. Proper curing and storage slows the rate of respiration of the winter squash fruit and will prolong the storage life.

After harvesting, cure the winter squash (except for the acorn types) at a temperature of 80° to 85° and a relative humidity of 80% to 85%. Curing helps to harden winter squash skins and heal any cuts and scratches.

Do not cure acorn squash. The high temperature and relative humidity during the curing process actually reduce the quality and storage life of acorn squash.

Storage

Winter squash fully cured and held at 50°-55° and 50%-70% relative humidity will last for 84-150 days.

Diseases

Anthracnose, Bacterial Wilt and Downy Mildew.

Pests

Squash Vine Borer, Squash Bugs and Cucumber Beetles.

Comments

After 1 or 2 fruits have set on a single vine, the vine should be cut back to within a foot of the last fruit to encourage production of the winter squash fruit.

References

Oregon State University, "Zucchini, Commercial Vegetable Production Guide", Last modified 1999-01-02, Oregon State University, http://www.oregonstate.edu/Dept/NWREC/pumpkin.html [1], Accessed 2003-05-21

Bradley, F. M. and Ellis, B. W.(Ed.). (1992), Rodale's All-New Encyclopedia of Organic Gardening: The Indispensable Resource for Every Gardener, Emmaus, Pennsylvania: Rodale Press.

Smith, E.C. (2000), The vegetable gardener's bible: discover Ed's high yield W-O-R-D system for all North American gardening regions., Storey Books: Pownal, VT.