Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
Growers with CSAs, sales to schools and institutions, or restaurant customers should consider storing and marketing winter squash. Winter squash include a wide range of types including butternuts and neck pumpkins, acorns, spaghetti squash, buttercup and kabocha types, delicata and dumpling types, hubbards, cheese pumpkins, and others. Many of these have the ability to be stored for long periods, especially butternuts, buttercups, and spaghetti types. New England has a tradition of eating large quantities winter squash; however, the further south you get, the less they are eaten. This may require customer education in order to market successfully. For example, butternut squash is great in soups, pastries, and casseroles and spaghetti squash is a fine low calorie, low carb, pasta substitute.
Having winter squash for winter sales requires proper handling and storage. Follow a regular fungicide program during crop production to produce disease free fruit to minimize postharvest fruit rots. Harvest when fruits are mature and prior to frost. Use care in handling fruit to prevent wounds. Wounding can negate benefits from a season-long fungicide program. Cure fruit after harvest at temperatures between 80 and 85°F (27-29°C) with a relative humidity of 75-80% for approximately 10 days. Temperatures below 50°F (10°C) cause chilling injury. The hard-shelled squashes, such as Butternut, Delicious, Spaghetti, and the Hubbard strains, can be stored at 55°F (13°C) and 50-70% relative humidity. Acorn squash will store for 5-8 weeks; pumpkins for 2-3 months and other hard-shelled squashes will store for 3-6 months. Research has not documented any benefit to post-harvest fruit fungicide dips.
For storage, a ventilated storage shed with supplemental heat works well. Basements are ideal. Empty greenhouses can be used if fans are run to keep the heat down in the day and heat is run to keep the temperature above 50°F (a significant cost). A cold room/box kept at 55° F will also work. Under these conditions, the longer keeping winter squash types can be kept in saleable condition through late winter, into spring.