The time of the growing season has arrived when pumpkins and winter squash are ready for harvest and storage. There is little growth and development after night temperatures become cool or foliage dies back because of disease or frost. The old belief that a frost is necessary before pumpkins and winter squash should be harvested is not true. In fact, frost on these two crops can shorten their storage life.
Pumpkin and winter squash have been an important source of food for humans for thousands of years. Members of the Cucurbita genus in the gourd family of flowering plants, both are native to the Americas from the southwestern part of what is now the United States through Mexico and Central America and south into Colombia, Ecuador and Peru.
The names pumpkin and winter squash commonly are used for several species including Cucurbita maxima, C. mixta, C. moschata and C. pepo. Many authorities place the large, orange fruit sold for autumn decoration in the species C. pepo, and assign winter squash as a common name to the other species. Interestingly, the canned product sold for making pumpkin pies actually is C. moschata, a species of winter squash.
Harvested properly and stored under good conditions, winter squash and pumpkin are among the longest lasting of vegetables. Fruits often may be stored and eaten until the time arrives in spring to plant next year's crop. Although prolonged storage can reduce eating quality, both of these vegetables still are a good source of vitamins A, C and K along with dietary fiber and other essential vitamins and minerals. Before modern production and shipping methods which provide us with fresh vegetables year around, they were essential for healthy eating during the long winter months.
Storage conditions for these two crops are different from those of many of vegetables. They prefer temperatures that are cool, but not cold. Temperatures between 50 and 55° F along with low humidity are ideal conditions for long-term storage. These are crops that should not be placed in outdoor pits or bulb cellars where relative humidity is high, and temperatures are cool.
Only fully mature pumpkins and winter squash will store well. The skin (rind) on them should be hard, and there should be no surface damage from handling or from insects. Any wounds can make the fruit more susceptible to rot that reduces storage life. Cut the pumpkin or squash from the vine with a portion of the stem remaining. An open wound which results when the stem breaks directly off at the base of the pumpkin or squash will reduce storage life. Also, it is important not to drop or toss these two vegetables. Bruises that might result from rough handling may not heal over and will reduce storage life.
Following harvest, pumpkins and winter squash benefit from a curing period to improve their keeping ability. If any surface scratches, insect feeding damage or other wounds from handling have occurred, curing under proper conditions helps to "heal" small wound by forming callus tissue. Curing and subsequent callus formation can prevent the entrance of rot-inducing organisms, when carried out promptly. The undamaged rind also will harden a bit more during the curing process.
Ideally, after pumpkins and winter squash are cut from the vine, they should be cured in a location where temperatures are close to 80° F for about 10 days. Such a location for the average gardener may be in a basement near the furnace, in a warm closet, or in an attic where temperatures normally do not run too high. After the 10-day curing period, they may be moved to a more permanent storage location. Pumpkins may be moved to a place for display or ornamental use immediately after the curing period.
For long-term storage of winter squash, well ventilated shelves kept at 50° F is ideal. At no time should the surface of the squash become wet from condensation or other conditions. Good air circulation around the stored commodity is important. Most of them will exhibit chilling damage if stored below 45° F and become more susceptible to rot. Conversely, at temperatures of 60° F or higher, they will lose moisture too fast and the flesh in them gradually will become "stringy."
Even under the most ideal conditions, some weight loss will occur due to cellular respiration and the constant loss of water. During storage there is a gradual change within the squash, so over a long storage duration, a gradual decline can be expected. However, this deterioration in quality is slowed greatly by proper storage conditions. The butternut and Hubbard types of winter squash are the best keepers.
Acorn squash is a winter squash that is an exception to the curing and storage conditions ideal for other winter squash. It should not be given the 80° F curing period, since it quickly become stringy at high temperatures. Instead, it should be placed under cooler conditions immediately following harvest.
Not many people make the effort to store pumpkins. Used mainly for autumn decorations, most pumpkins are discarded following Thanksgiving. This is unfortunate, since pumpkins are quite nutritious and discarding them represents a waste of valuable food. Closely related to winter squash, pumpkins require the same curing period described above to allow any wounds to heal and to harden their rinds. Following curing, store in a single layer at 45 to 50° F. Provide good air circulation to avoid moisture from forming on the rinds which is an invitation for rot to form. Check the store pumpkins frequently and discard any that have begun to decay.
Additionally, pumpkin pulp can be frozen or canned. These preservation methods represent ways to give jack-o'-lanterns added value, as the pulp is scooped out of the pumpkins to ready it for carving. Additionally, strips of pumpkin "flesh" can be dried or pickled for later consumption. In all cases, make certain to follow proper food preservation safety measures.