Autumn joys are here! For me, walking through a pumpkin patch to select colorful fall decor and handling oddly-shaped gourds are seasonal highlights that make me happy from top to bottom. A close relative of those curious plants in the cucumber family (Cucurbitaceae) are winter squash. Pumpkins, gourds, and winter squash are all members of the genus Cucurbita (Latin term for gourd). Winter squash, also known as Cucurbita maxima, Cucurbita moschata, and Cucurbita pepo, are warm-season annual vines that climb up fences or grow along the ground.
Native to South America, winter squash plants were first domesticated in Argentina, Bolivia, and Uruguay. Although you can find them in grocery stores throughout the year, you typically see piles of these striking Cucurbita in local markets during October and November. These plants grow and produce fruit in the summer season, but they can be stored during fall and winter, which explains their common name: winter squash.
You are probably familiar with some colorful varieties of winter squash, often used for decorative fall arrangements. Their simple leaves are rounded and unlobed, but the actual shape will vary among species. Squash leaves tend to be large to shield developing fruit from overexposure to sunlight. The stems have vining habits and are usually thick and textured.
Cucurbita are monecious, with separate male and female flowers on different parts of the same plant.  The beautiful flowers are yellow, with deep cups composed of five petals. Male flowers, which appear first, have long, thin stems with a single protruding stalk inside that’s full of pollen. Female flowers have shorter stems with a bulging base and three thick stalks inside. Small insects crawling around in these flowers are a common sight, and their job is to transfer pollen from male to female flowers. This ensures pollination and subsequent fertilization to produce seeds. Without those processes, squash plants would not bear fruit.
Winter Squash Varieties
The bright colors and diverse shapes of winter squash are intriguing. In fact, you might never guess that some of these varied specimens are even related. This article describes five distinct types that are easy to prepare for use in cooking and baking.
Hubbard squash has several names, including buttercup and green pumpkin. It can grow to be rather large – up to 50 (22.7 kg) pounds. The gray to greenish-blue skin is very tough and hard to cut, so this squash is sometimes sold in pre-cut pieces. The deep orange flesh inside is noticeably sweet and highly nutritious. Hubbard squash can be boiled, roasted, steamed, sauteed, or pureed for consumption.
Acorn squash is dark green with splashes of yellow or orange on its tough outer skin. This squash has the same shape as an acorn (minus the top hat) with a slightly pointed end and smooth ridges that run longitudinally from top to bottom. Acorn squash weighs from one to three pounds, and its flesh is golden in color. This squash can be baked, stuffed, steamed, or microwaved and is an excellent substitute for pumpkin in favorite pie recipes.
Delicata squash, sometimes called peanut squash, is oblong in shape and approximately six inches long (15 cm) and three inches across (75 cm). The outer skin is creamy colored with green stipes, and the flesh is light yellow and pleasantly sweet. Delicata skin is tender and can be eaten, but this thin exterior shell decreases the length of time that this squash can be stored.
Tan-colored butternut squash is shaped like a bottle with an elongated neck and bulbous end. The inner flesh is bright orange and rather dense with a buttery, nutty flavor. Butternut squash can be roasted, steamed, or cut into smaller pieces to be sauteed and pureed for use in soups or as a delicious filling in pasta recipes.
Finally, there’s spaghetti squash, which could easily win first prize for being unique. Its thin yellow skin contains a delightful surprise inside. After cooking this Cucurbita, remove the yellow flesh with the tines of a fork, and what comes out is a stringy set of thin strands that resemble spaghetti. Use this savory-tasting squash in a vegetable medley or simply add tomatoes, basil, and grated cheese for a fresh, yummy look-alike of angel hair pasta with sauce.
That’s just the beginning! Have fun exploring more varieties of winter squash, such as Banana, Turban, Cushaw, Calabasa, or Kabocha. Or try tasty new adventures by roasting smaller squash with thin, edible skins, such as Sweet Dumpling and Carnival. The common denominator for the firm flesh of every type of winter squash is versatility and nutritional value. Whatever cooking method you choose, the rich flavor of Cucurbita will prevail. Winter squash are rich sources of beta carotene, vitamin C and B6, and fiber, and all are packed with protein, magnesium, and potassium.
Cultivating Winter Squash
Most winter squash species have similar seeds: thin beige teardrops about ½ inch in length. Sow Cucurbita seeds in late spring when the soil has warmed up to a temperature of at least 60° F and after the last frost date. Plant seeds at a depth of one inch in fertile, well-drained soil. Mound the soil first and then plant seeds at the center of the “hill top” where the soil is warmer.
Squash thrive in full sun and need sufficient area for their sprawling vines to spread out. If there’s limited space for planting, place squash near the edges of a garden and let vines grow outward into the lawn. Mulch areas around the seeds to retain moisture, prevent weed growth, and protect the shallow roots that develop on squash plants. Cucurbita need plenty of water, and because they are heavy feeders, organic fertilizer should be added to the soil periodically.
A potential problem for Cucurbita is the presence of squash bugs, which are notorious for ruining squash crops. Look for tiny egg clusters on the underside of leaves and scrape them off right away. Or, spray neem oil on the eggs and the young squash bugs before they inflict damage on the plants.
Harvesting and Curing Winter Squash
It’s generally best to wait until late September or early October to harvest winter squash, but some may be ripe and ready to go in August. Harvest the fruit when it’s fully mature. Look for firm, shiny skin and vines that are starting to dry out. Cut the stem with a sharp knife or pruners (avoid tearing) and leave at least one inch on the fruit.
Cure winter squash to dry off any extra moisture and harden the skin; this keeps bacteria and fungi out. Place squash in a warm, dry area indoors, such as on a sunny windowsill. After that, dip the Cucurbita into a rinse of low-concentration bleach solution (5 cups water plus ½ cup bleach) to sanitize the outer covering. Next, the squash is ready for storage in a dark room with good air circulation. It can be stored for a month or more, but be sure to check every few days for any indication of decay.
Enjoy the fruits of your labor and superb health with tasty recipes that call for winter squash!
References in Print
Philips, Roger and Rix, Martyn (1993). The Random House Book of Vegetables. New York: Random House.
Online Resources
Winter Squash in the Home Garden (Penn State Ext.2020)
Cucurbita maxima (winter squash): Go Botany (nativeplanttrust.org)
Cucurbita maxima – Plant Finder (missouribotanicalgarden.org)
Yard and Garden: Harvesting and Storing Winter Squash | News (iastate.edu)
Winter Squash | The Nutrition Source | Harvard T.H. Chan School of Public Health