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Zucchini, a member of the summer squash family of cucurbits (Cucurbita pepo), owes its name to the Italian word for a small pumpkin or squash, zucchina.

Historians believe squash was first grown in Central and South America, then taken to Europe where Italians more fully developed summer cultivars such as zucchini.

Zucchini is also called courgette, a variation of the French word courge, meaning squash, or referred to as a ‘marrow’ vegetable in Great Britain.

Widely considered a vegetable, botanically, zucchini is a fruit. Many dishes include use of both (raw or cooked) squash as well as its delicate flowers (frequently battered and fried).

Although zucchini can grow up to several feet in length, most is harvested and consumed while immature, before the hardening of seeds and rinds and a corresponding loss of flavor and quality. In South Africa, zucchini is mostly grown and harvested as a baby vegetable, called baby marrow.

Generally the most popular of the summer squashes, demand for zucchini continues to grow steadily in the United States. It can be grown nearly anywhere with consistently warm summer temperatures. To keep up with demand, the United States is the world’s top importer, sourcing primarily from Mexico.

Seasonal Availability Chart

Types & Varieties
Zucchini coloring ranges from light green to very dark, almost black-green, can be striped or speckled, and is usually smooth, straight, and cylindrical with a glossy surface.

Other variations include golden or white zucchini (though the latter is often considered a mutation), and rounder, ball-shaped varieties.

Average size ranges from 5 to 6 inches for shorter varieties (for example, Caserta) to well over a foot for longer types like Cocozelle. Overall, most zucchini are harvested in the 7- to 8-inch range. Baby fingerling zucchini, as its names suggests, is picked when only a few inches long.

Among the varieties and hybrids are Ambassador, Aristocrat, Black Beauty, Blacknini, Classic, Eight Ball, Elite, Gold Rush, Greenbay, Mexican Globe, Payload, Seneca, Spineless Beauty, and Tigress.


Zucchini grows rapidly in temperate climates with full sun and loamy soil, producing both male and female flowers (though only the females produce fruit).

Overly plentiful male flowers should be culled every few days, and mature zucchini left on the vine will prevent additional fruit from growing.

Most fruit grows within a week of flowering with optimum tenderness when at 6 to 8 inches in length, a diameter of 3 to 4 inches, and thin, wrinkleless skin with no soft spots.

Care should be taken in handling immature zucchini, as the fruit is prone to bruising and scratches.

Pests & Diseases
Cucumber beetles will attack seedlings, vines, and growing gourds, while the aptly named squash bugs damage vines and attack maturing fruit.

Squash vine borers are an annual nuisance due to overwintering in the soil, particularly for winter squash, but can damage zucchini when larvae bore into vines and prevent moisture absorption. Symptoms are often mistakenly attributed to bacterial or fusarium wilt but can be confirmed by holes at the base of wilted leaves. Other pests include aphids, cutworms, leafminers, mites, mole crickets, and whiteflies.

A lack of calcium will cause blossom end rot, the formation of watery, black bloating at the ends of fruit, most commonly found in tomatoes.

Angular leaf spot is a bacterial disease that can affect zucchini, cucumbers, and honeydew melons. Phytophthora blight is a fungal disease that can decimate zucchini and other cucurbits, destroying entire fields.

Mosaic viruses and mildew (powdery and downy) can appear on foliage. Given the faint, green-grey markings on mature zucchini leaves, these splotches and streaks can be mistaken for mildew, but are normal.

Storage & Packaging
Since harvested when immature, zucchini is not ideal for lengthy storage. This summer squash will lose moisture and deteriorate quickly, but can be stored for a few days from 41 to 50°F with high humidity. Zucchini does not ripen after harvest and can be mildly sensitive to ethylene-producing fruits and vegetables.

References: North Carolina Cooperative Extension, University of Arizona Cooperative Extension, UC Davis Postharvest Technology Center, University of Florida/IFAS Extension, University of Georgia, University of Illinois Extension, USDA.


Generally speaking, the percentage of defects shown on a timely government inspection certificate should not exceed the percentage of allowable defects, provided: (1) transportation conditions were normal; (2) the USDA or CFIA inspection was timely; and (3) the entire lot was inspected.

U.S. Grade Standards Days Since Shipment % of Defects Allowed Optimum Transit Temp. (°F)
10-5-1 5

There are no good arrival guidelines for this commodity specific to Canada; U.S. guidelines apply to shipments unless otherwise agreed by contract.

References: DRC, PACA, USDA.


• There are no size requirements (diameter or length) in the U.S. grade standards for summer squash
• Bruising is scored as a defect when any indentation is more than 1/8 inch in depth or exceeds an area of 1/2 inch in diameter
• Scuffng is scored as a defect when affecting more than 10% of the surface or when discolored, affecting more than 5% of the surface area
• Any amount of decay, including decay affecting the stem, is scorable against the 1% decay tolerance
• A gummy substance can exude from squash, particularly from cut or broken stems; this shall not be scored as decay unless the underlying flesh is breaking down.

Source: Tom Yawman, International Produce Training,

This information is for your personal, noncommercial use only.