New Market, Va. ? Back when I was growing up, kids would measure the length of their summer vacations against what was happening in the family garden.

Around Memorial Day or about the time of the class picnic, the threat of the last frost had passed and the ground was warm enough for planting watermelon seeds. It would take 80 days or so for “Big Bertha” to reach its 40-pound maturity.

Some of the early sweet corn varieties would grow knee-high by the Fourth of July. A few of the more literal-minded among us would walk the cornrows, holding stalks against their legs as a blue-jean kind of yardstick.

Back-to-school sales would begin blooming along with the sunflowers. The towering plants were eye-catching reminders that summer was fading fast and the buses soon would be rolling again.

Excellent learning labs, gardens. And great teaching aids, sunflowers. Summers spent hoeing, mowing and gathering were wonderful opportunities for backfilling our many educational gaps.

“Horticulture is a nice educational tool because it has so many aspects,” says Cynthia Haynes, an extension specialist for consumer/urban horticulture with Iowa State University at Ames. “It teaches science, health and nutrition, how things work and how things change with variables.”

Sunflowers are a great educational tool for kids. They're easy to plant and quick to grow.

Sunflowers are among the best show-and-tell aids in nature, says Haynes, who among other things teaches a classroom course titled Educating Youth through Horticulture.

“Sunflowers are easy to plant and easy to grow. They demonstrate utility or how to make oil and use the seeds for snacks or birdfeed. They’re like most plants in that they’re biodegradable. They improve the soil for the next year,” she says.

Sunflowers are thought to have had their beginnings in Central America and the American Southwest, where they were used to supplement the daily diet as well as for dyes, medicines and building materials. Credit the latter-day Russians with developing them into an important source of edible oil, behind only soybeans and cottonseed.

Now they’re back in their ancestral home as a short-season agricultural crop, maturing in about 90 days. That makes them desirable for the chillier climes of the North or for the double-cropping systems of the South. The “confectionary crop,” or about 25 percent of all U.S. sunflower production, goes to the birdseed market or is sold as a snack or recipe ingredient.