Squash (genus Cucurbita) is an annual plant belonging to the Cucurbitaceae family and native to the Americas. Squash may have been domesticated as early as 7000 to 5000 BC in the Tehuacan Valley of Mexico; evidence suggests that it was cultivated in present-day Ontario by the Huron and related groups by about 1400 AD. Both running and bush types occur. Squash have large yellow flowers that attract bees; each plant carries male and female flowers. Squash are classifed as either summer or winter varieties, depending on when they are harvested.

Summer squash (mainly C. pepo) are harvested before maturity, when they are still small and tender; common varieties are zucchini and yellow crookneck. Winter squash (mainly C. maxima, but also C. pepo, C. moschata or C. mixta) are harvested at full maturity (3-4 months after planting), when the rind is hard; common varieties are acorn squash and butternut squash. Winter squash have a higher carbohydrate content and are more nutritious. Squash grows rapidly, producing abundant foliage and a well-developed but rather superficial root system. Summer squash is normally seeded directly in the field, as is winter squash if the growing season is long enough. Winter squash can be stored at about 10°C, under dry, well-ventilated conditions. Squash species crossbreed readily; numerous cultivars vary enormously in shape, colour, size and texture.

The squash has a low commercial value in Canada, although its popularity has been growing over the past 30 years. There are now more than 6500 ha of land planted with squash every year; the crop is worth more than $40 million. Over 90% of squash sales come from fresh squash; the rest is from processed squash products. Squash are also increasingly being used as a tourist attraction in the agri-tourism industry. Quebec and Ontario are the two main squash producers in Canada.