This article was originally published on March 19, 2009 and expired on September 1, 2009. It is provided here for archival purposes and may contain dated information.
Squash are technically a fruit since they develop from the swollen ovary of the blossom, but they are commonly referred to as a vegetable, said a University of Illinois Extension horticulture educator.
"They are a very large group, with hundreds if not thousands of varieties," said Jennifer Schultz Nelson. There are two major groups: summer squash and winter squash.
"Zucchini are a specific type of summer squash. Summer squash have thin tender skin, mild flavor and are harvested while young and immature. If allowed to mature, the seeds and flesh are tough, and many gardeners will testify that left unattended, summer squash will assume enormous proportions in a short time."
The other group of squash is winter squash, which are harvested late in the season when they are mature. Their skin is very thick, housing very flavorful flesh that stores well and is a staple in many homes over the winter months.
"The zucchini traces its origin to the native summer squash in Central and South America," she said. "European explorers brought these summer squash back to Europe, where they became popular with nearly everyone except the French. They considered the squash inferior until they learned to use the young tender fruits which were much more palatable than the fibrous mature fruit."
The Italians are credited with developing what we now call zucchini. It is widely thought that a chance mutation in an existing summer squash gave rise to the squash we now call zucchini in the late 1800s near Milan. The Italian words "zucca, zucchini, and zucchine" are the singular and plural words for squash, giving rise to the name zucchini that we use today.
"Zucchini didn't make it to the United States until the 1920s, when Italian immigrants brought seeds with them to California," Nelson explained. "A small southern California seed company began distributing seed a short time later, but zucchini didn't catch on with the rest of the United States until the late 1930s.
"Today zucchini is a common sight in homeowner vegetable gardens and restaurant menus."
Growing zucchini is fairly simple, and the plants produce so well that some gardeners have to come up with schemes to sneak them into neighbor's hands. One group of Pennsylvania gardeners dubbed August 8 "National Sneak Some Zucchini Onto Your Neighbor's Porch Night."
There are many different variations of zucchini available in seemingly all shapes and sizes.
A favorite of mine is 'Roly Poly' that is small and round," she said. "It makes a perfect individual serving when stuffed. 'Gadzukes' grows with raised ridges along the outside, and slices look like little stars."
Common pests of zucchini are cucumber beetles and squash vine borer. Black striped yellow cucumber beetles feed on the plant, or their larvae feed on the roots and can spread a bacterial wilt that will kill the plant.
"There is no way to save a plant that has contracted this bacterial wilt," she said. "The affected plant should be removed from the garden and destroyed. Using row cover fabric which lets in light, but not insects, will help prevent the beetles from feeding on the vines."
Squash vine borers cause a sudden wilting of the plant, and left untreated will kill the plant. They bore into the lower portions of the stem and eat their way through the stem tissue. A characteristic sawdust-like yellow frass around squash stems is a telltale sign that vine borers are present. Frass is what the vine borer leaves behind after digesting the stem tissue.
"If caught early, the individual borers can be removed by carefully slitting the stem open with a knife," she said. "Moist soil should be mounded over leaf joints at higher points to encourage secondary root formation, since the borer's feeding has likely disrupted the main roots. A cultural way to control these pests is to remember to rotate crop location in the garden each year."
Chemicals effective for both cucumber beetles and squash vine borer are carbaryl and malathion. Avoid using both chemicals together as they can be toxic to the plant. Remember to read and follow label directions.
"Despite some potential for insect pests, zucchini are a perfect crop for both beginner and seasoned gardeners alike," said Nelson.
Source: Jennifer Nelson (Schultz), Extension Educator, Horticulture, email@example.com
Pull date: September 1, 2009