Squash can be categorized into two groups: summer squash and winter squash. Summer squash such as zucchini tend to be harvested during the summer while the squash is still immature. The ideal summer squash are harvested very early when the squash blossom is still attached to the vegetable. The entire vegetable including skin, flesh, and seeds, are all edible. Winter squash such as pumpkin and butternut squash are fully ripened squash harvested in the late fall to winter. They have a tough rind and only the flesh is generally eaten. If summer squash are left on the vine they will grow and their skin will thicken until they resemble winter squash.
All of the varieties of summer squash are thought to be descended from a single ancestor (Cucurbita pepo) that is native to a large region spanning throughout Mexico and Texas. This ancestor could thrive in a wide range of temperatures and natives had cultivated it for centuries. Early European explorers took summer squash back to Europe where they were very popular, especially in French and Italian cuisine. Today, summer squash is grown in many areas of the world, from the Americas to Europe to Africa. In many areas of the world, especially in Europe, summer squash may be called "vegetable marrow."
The most common varieties of summer squash include:
- Zucchini AKA courgette: The easiest to find of the summer squash, zucchini are long and cylindrical with deep green skin and cream flesh.
- Pattypan squash: A round and flat squash with a scalloped edge roughly three inches in diameter. Pattypans can have yellow or green skin depending on the variety and all have white flesh.
- Crookneck/straightneck squash: Both types of this long squash have a thicker, bulbous end on one side and a thinner end on the other. The thin end of the crookneck squash is curved while the thin end on the straightneck squash is straight. Both types have pale yellow skin with light yellow flesh.
- Chayote AKA mirliton: This squash actually is a different species (Sechium edule) than the other summer squashes. It is small and somewhat round with light green skin and cream-yellow flesh.
Purchasing and using summer squash
Many kinds of summer squash, especially zucchini, are available in most regions year-round. However, the best time to buy fresh squash is during the early to mid summer. Look for squash with soft, undamaged, and glossy skin and firm flesh. Smaller squashes tend to be more tender and have more flavor. Summer squash does not store as well as winter squash and should be refrigerated for up to two weeks. Don’t wash them until you are ready to use them.
All varieties of summer squash have the same pleasantly mild flavor and can be used interchangeably in recipes. Wash the squash well and remove the ends. Most of the healthy carotenoids and other nutrients are present in the squash’s skin, so try to avoid peeling them. They are delicious eaten raw alone or in salads. The squash can also be cooked, but try to cook them as quickly as possible to preserve flavor. The squash can be boiled, steamed, sauteed, grilled, and roasted. A simple touch of salt and black pepper and maybe a bit of butter adds flavor without overwhelming the squash. Fresh or dried herbs such as basil and oregano also go well with the squash. Summer squash can also be cubed and battered and fried for a delicious appetizer. Larger squash can also be stuffed with a vegetables, beans, or grain mixture and baked. Cubes or grated pieces of summer squash add flavor and texture to soups and stews, vegetable dishes like ratatouille, and sweets like muffins and quick breads.