Surely, zucchini must have been with us always. It is one of the most widely grown crops in the world, with substantial harvests in North and South America, Europe, India, the Middle East and Asia. More than 6 million tons of summer squash are grown every year around the world, with zucchini accounting for the lion’s share in almost every location. Sometimes it seems that much is grown in each of our neighborhoods alone. Every summer we struggle to come up with new ways to cook it, fighting to keep our heads above what seems to be a rising tide of squash. We stuff it, stew it, sauté it, steam it and serve it raw in salads. And still we never seem to make a dent.
So it may come as a surprise to learn that zucchini, which seems so ancient, is actually a relatively modern invention, probably dating back no earlier than the turn of the twentieth century. According to squash historian Harry Paris, the first recorded mention of zucchini came in a 1900 Italian seed catalog. It probably didn’t make its way to the United States until after World War I, brought by Italian immigrants to California.
Why the doubt? How hard can it be to spot a zucchini? Actually, it can be pretty danged difficult. Certainly, there were cylindrical green summer squash harvested much earlier than the twentieth century. A basket of them, flowers attached, appears in Fruttivendola, a well-known sixteenth-century painting of a fruit and vegetable merchant by Vincenzo Campi. But those aren’t zucchini. They are cocozelle, one of zucchini’s forebears. There are also records of cylindrical green squash being harvested throughout the eastern Mediterranean since fairly shortly after Columbus’s voyages. These are not zucchini either, but marrow squash. To make matters even more confusing, all three of these are just broad families; within each are dozens, if not hundreds, of individual varieties. And those are just the cylindrical green ones. Summer squash also come in other colors and shapes. At the Newe Ya’ar Research Center in Israel, Paris grows more than 320 varieties he has deemed of special interest.
Making sense of all this squash is not nearly as complicated as it may seem. Start with the cylindrical green ones, since they are now the most popular. Zucchini are dark green and show little or no taper along their length (they are roughly the same circumference at the flower end as at the stem end).
Marrow squash are generally pale to grayish green in color and tapered in shape (they are bigger around at the flower end). Still preferred in the eastern Mediterranean and Latin America, they tend to have denser flesh than zucchini and so hold their shape better in soups and stews.
Cocozelle, which are mostly grown in Italy, are longer and thinner than zucchini and slightly bulbous at the flower end. Whereas a zucchini is usually 3½ to 4½ times as long as it is wide, cocozelle can be 8 or more times as long. The distinctions between the two are more than in shape and color, though. Cocozelle tend to have a richer flavor than zucchini.
But, of course, nothing is quite that simple. Squash are notoriously promiscuous. More than one hundred specific varieties of zucchini are grown today, and many of them are crosses between true zucchini and either marrow squash or cocozelle (sometimes both). Knowing this background makes it easier to guess the qualities of the squash you see. If it is dark green and extremely thin for its length, it probably has some cocozelle lineage and a fairly strong flavor. If it is pale green and slightly bulbous, it is more likely to have denser flesh.
In addition to these cylindrical green varieties, three other families of summer squash are popular. Crookneck squash are yellow, with narrow, bent necks and bodies that become quite bulbous toward the blossom end. Straightneck squash are similar, except the necks are not bent. (Just as all cylindrical green squash are sometimes lumped into one family, so are the crooknecks and straightnecks.) Scalloped squash, which can be either yellow or green, are flattened with scalloped edges.
All three families are mildly squashy and less richly flavored than good zucchini. Still, until the advent of the zucchini, they were the most popular summer squash grown in the United States, and quite a bit of regional allegiance to them lingers. Crooknecks are especially popular in the Southeast, while straightnecks are preferred in the Northeast. Scallops, which once had pretty universal popularity, are beginning to make a commercial comeback after having fallen from favor—though not in the range of varieties that were once available.
The relatively new Golden Zucchini, released in 1973, is also becoming popular. And at farmers’ markets you may see round zucchini, such as the several Italian varieties called Tondo and the Provençal Ronde de Nice. These are not true zucchini, but can be more accurately described as “summer pumpkins.” They have firm flesh and mild flavor similar to a marrow squash.
All of these summer squash are harvested at various stages of immaturity, usually within a week of their flowers becoming fully open. Left to grow indefinitely, they would become almost as big and hard-shelled as their pumpkin cousins. But whereas pumpkins develop dense, sweet flesh when fully grown, summer squash get spongy and watery. This is particularly true of crooknecks, which even when fairly small can have hard, warty skin and a mushy interior. Zucchini are usually harvested when four to five inches long, though sometimes they are picked at little more than an inch (and in this case frequently with flowers still attached). Up to six or seven inches long, zucchini are good for stuffing, as the spongy center is removed. Much bigger than that, and the squash quickly becomes bitter with fully developed seeds and pith—the stuff of zucchini jokes.
Unlike the flowers of most vegetables, squash flowers can be eaten as well as the fruit. They have a delicate flavor reminiscent of the squash itself. Dip them in a simple flour and water batter and deep-fry them either as they are or stuffed with a little meat or cheese. Or chop them up and stir them into a risotto, a frittata or a stew for stuffing a quesadilla. This is most commonly done with zucchini flowers, but other squash flowers, including pumpkin flowers, can be used as well. These flowers can be either female (with the fruit attached) or male (no fruit, intended only to produce pollen). A single plant will produce flowers of both types. Because they are so delicate, squash blossoms must be used the day they are picked and so are rarely found in groceries. If you want them, you’ll have to cultivate a farmers’ market grower or your neighborhood gardener. If the grower is reluctant, just remind him that the more flowers he sells, the fewer zucchini he’ll have to worry about.
WHERE THEY’RE GROWN: Despite their name, summer squash are actually mild-weather crops and are available on a fairly constant basis throughout the year. Three states lead the market—Florida, California and Georgia—but it is a slim lead indeed; the top five states account for less than 55 percent of the squash grown. Squash sales are booming—consumption has increased by almost a third in the past decade. To keep up with this demand, imports—almost entirely from Mexico—have become an important part of the supply picture, accounting for almost 40 percent of the squash consumed in the United States (530 million pounds imported vs. 885 million pounds domestic).
HOW TO CHOOSE: Whatever the type, summer squash should be firm and free of wrinkles and nicks. Really fresh squash will bristle with tiny hairs. The zucchini and its relatives and scalloped squash should be deeply colored, but crookneck and straightneck squash should be pale—by the time their rinds have turned gold, they will be hard and warty (this is not true of Golden Zucchini).
HOW TO STORE: Summer squash are fairly perishable and should be cooked within a week of harvest. They should be refrigerated until ready to use, sealed in plastic bags to slow respiration. Do not wash the squash until right before cooking, as any moisture on the skin will make it spoil faster.
HOW TO PREPARE: Summer squash are eaten whole, peel and all, so the only preparation necessary is removing the remains of the stem and any scar at the blossom end. Since squash cook fairly quickly, it makes a big difference how thick it is cut. Sliced thin, it will melt away to a rough puree. If you want pieces to remain intact, cut it into thicker sections.
ONE SIMPLE DISH: Summer squash is the perfect vegetable for braising. Cut it up and cook it with a little olive oil, about 2 tablespoons water and some garlic in a covered skillet over medium-high heat. When the squash begins to become tender, remove the lid and increase the heat to high. Cook, stirring constantly, until the squash begins to glaze.