Sustainable Practices for Vegetable Production in the South
Dr. Mary Peet, NCSU
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Squash, Gourd, and Pumpkin

HARVEST AND POST-HARVEST

Summer squash. Harvest generally starts 40 to 50 days from planting and 3 to 6 days after flowering. Daily or alternate daily harvests are required because squash fruit average 0.75 inches growth per day during this period. Fruit should be no longer than 7 to 8 inches at the time of harvest to be considered top quality in eastern markets.

Like most immature fruit, summer squash is highly perishable and easily blemished. Pickers should wear soft cotton gloves and use great care in extracting the fruit through the leaves to prevent scarring which quickly oxidizes to brown discoloration. Summer squash can be stored for only 2 to 3 weeks at 45 degrees F and 80 percent relative humidity, and it is susceptible to chilling injury. Fruit set and development will continue throughout the season if older fruit are removed. Average summer squash yields are 5 to 8 tons per acre.

Winter squash and pumpkins. Winter squash generally need a 120-day growing season for fruits to reach maturity before harvest. Fruit quality and storage life are reduced if the fruit are harvested before maturity, but fruit quality is also reduced if fruit are left in the field until frost. Winter squash are mature when the rind resists thumbnail pressure. A field is normally only harvested once.

Squash are cured for ten days at 80 to 85 degrees F with 80 to 85 percent relative humidity to harden the rind. It is better to plant in July than to try to hold pumpkins in the field or in storage for Halloween. If pumpkins must be harvested a long time before sale, they should be washed, dipped in a 10 percent bleach solution and stored in a dry place to reduce postharvest rots. Storing in the shade also reduces rots. Pumpkins sold for jack-o-lanterns must have enough stem attached to make a good handle. Care should be taken, especially if pumpkins are slightly immature, to avoid lifting the pumpkin by its stem at harvest.

Storage times for pumpkins and winter squashes (after curing)

. Time (Months) Temp.(F)* % Rel. Humidity Comments
Pumpkins 2 to 3 50-55 50-70 Do not store with apples
Hubbard squash 5 to 6 50-55 50-70 Fruit surface must remain dry. Use forced air ventilation if necessary
Butternut 2 to 3 50 50 .
Acorn squash 1 to 2 50 50-75 At temperatures over 55 degrees F, surface yellows and squash becomes stringy.

* If higher storage temperatures are used, starches break down into sugars which reduces storage life.