All pumpkins and hard-shelled winter squash may be stored at the end of the growing season for use well into the new year. For best results, store sound, well-cured fruit at 50°F to 55°F in a relative humidity of 50% to 70%.
Length of storage life varies according to variety and type of squash or pumpkin.
Storage life
Hard-shelled winter squash and storage life
- Table Queen (acorn type): one to two months
- Butternut: two to three months
- Hubbard types: three to six months
- Banana: three to six months
- Buttercup (turban type): three to six months
- Sweet Meat: four to six months
Pumpkins and storage life
- Jack O'Lantern: two to three months
- Connecticut Field: two to three months
Table Queen and other acorn-type squash can be stored satisfactorily for one to two months. With longer storage, the skin begins to turn yellow and the squash becomes stringy.
Harvesting
Harvest all types of squash and pumpkin before frost begins. Squash are ready for harvest when the rind is hard enough to resist fingernail scratches. Cut the stem 2 to 4 inches from the fruit. Pumpkins without stems do not store well. Hubbard-type squash stores best with the stems completely removed. Handle fruit carefully to keep them in good condition.
Slightly immature squash and pumpkin can be used if they are cured properly. Curing helps toughen the skins of immature fruit and helps heal cuts and scratches.
Curing
All squash undergo a slow curing process during proper storage. Artificial curing is not necessary for well matured squash under good conditions.
Nearly mature squash, except acorn types, may benefit from a short period of curing. Curing is holding squash and pumpkin at a temperature favorable for healing cuts and scratches and for forming a protective corky layer over injuries and cut surfaces of the stem.
Cure squash and pumpkin for 10 days at temperatures of 80°F to 85°F and a relative humidity of 80% to 85%. Use a small cabinet heated by a thermostatically controlled electric heater or a corner of the garage partitioned off with plastic for a curing chamber. A small fan will maintain good circulation and uniform distribution of heat.
Storing
Squash and pumpkin deteriorate rapidly if stored at temperatures below 50°F. The best storage temperature is between 50°F and 55°F.
Fruit that has been exposed to freezing before harvest also will deteriorate rapidly. A relative humidity of 75%, about normal for garages or other suitable storage areas in western Oregon, is satisfactory. Keep the temperature at 50°F to 55°F.
Keep the surface of the fruit dry to prevent or retard growth of decay fungi and bacteria. Air circulation helps to prevent moisture from forming on the surfaces of the fruit.
Provide shelves for storage of pumpkin and squash. Do not store fruit on cold concrete floors. Promptly discard any fruit that shows signs of decay. Some of the more durable squash may be stacked on top of each other if adequate room is provided for air circulation.
Do not store pumpkin or squash near apples, pears or other ripening fruit. Ripening fruit releases ethylene gas, which causes yellowing of the squash and shortens storage life.
Research with muskmelons suggests that pumpkins and winter squash may benefit from being dipped in 135°F to 140°F water for three minutes, and dried quickly before storage. Warm, wet fruit are subject to invasion by microorganisms. Therefore, drying and cooling to the storage temperature should be done immediately following this treatment. This hot water treatment surface sterilizes the fruit. No benefit has been found from chlorination of the hot water, but gently wiping the surface clean with 1 part household bleach in 10 parts of water may be helpful.