STRANGE THINGS sprout in Skagit Valley’s fields: Monster plants with six-foot stalks covered with yellow flowers, delicate ferny-leaved things with round white heads holding hundreds of tiny blossoms, and unruly tangles of leaves, spears, and spikes.

John Roozen ’74, whose family’s name is synonymous with Skagit Valley tulips, keeps careful watch on these fields. He swings his pickup over to the side of the road and dives into a field, a curly, hairy mess of green. He plucks off the tip of a plant and hands it over. See that, he says, pointing at the dozens of small green nuggets clustered along the stem, those are spinach seeds. Next year they’ll be grown into plants in California or Arizona and harvested for those fresh-washed packages of baby spinach that have become so popular.

While the valley is famous for tulips, most people don’t know that 75 percent of the nation’s spinach seed comes from here. The region is one of the rare spots in the world where spinach seed can be grown, says Don McMoran, the Skagit County WSU extension agent. And it’s a complicated crop. Because of fungus concerns, for example, spinach for seed must be in a lengthy rotation, sometimes not returning to the same field for 12 to 15 years.

Most other places have the wrong climate. The East Coast is too hot and humid. And in well-known agricultural settings like California, “the summer days are just too short,” says Lindsey du Toit, a WSU plant pathologist who works at the Northwestern Washington Research and Extension Center in Mount Vernon. Places like Salinas Valley may be ideal for growing spinach plants to harvest for eating, but to get seed “you have to have long days and mild summers.” And for that, Skagit Valley is ideal.

The August day of my drive through the valley with Roozen is a prime example. It’s in the 60s and, while clouds fill the sky, the sun breaks through and traces its way across the valley floor. A soft rain falls intermittently.

Washington’s seed history started the late 1880s, when an entrepreneur named Alvinza Gardner Tillinghast opened a seed company in the valley and began contracting with local farmers to grow cabbage seed, which he then packaged and sold around the country.

Early Skagit Valley farmers like James H. Hulbert Sr. experimented with what crops would grow best in the alluvial soil. In addition to running a dairy, his family raised vegetables for seed for a collection of local companies. Today his grandsons Tom and Jack Hulbert ’85 run Skagit Seed Services Inc., one of the five major seed producers in the valley.

What Tillinghast, Hulbert, and their descendants figured out is that northwest Washington is an ideal location for growing seed for vegetables like spinach, radish, and cabbage (again, Washington provides the majority of the nation’s cabbage seed).

Seed production spread east across the Cascades in the 1950s, after the Columbia Basin Project brought irrigation to nearly 700,000 acres. The land there is well suited to a variety of seed crops including carrots, onions, parsley, dill, radish, kohlrabi, and turnips.

While our state is a great place to grow seed, doing so is not always an easy feat, says du Toit. In addition to the challenges brought by disease and weather, plants like carrots and cabbage are a biennial endeavor. They have to go through certain conditions to induce them from vegetative to reproductive growth. For that they require an extended period of cold weather (winter). Then in spring, when the weather warms, the plants will bolt. With cabbage, it’s particularly spectacular, because the plant’s head splits open and the seed stalk pushes up, says du Toit.

Some cabbages are bound by tight wrapper leaves that won’t give way to the stalk, so workers have to go through the fields with knives and slit the tops. Then there’s a complete transformation. As the stalk grows from the head, it can get up to five or six feet tall. It will produce bright yellow flowers, making a field that, to the untrained eye, looks like anything but cabbage. The flowers must be pollinated by honey bees, and sometimes the tall stalks fall down on themselves. To prevent this, the growers have to go through and stake them. “It’s a very labor intensive crop,” says du Toit. But if the bees do their job, each flower will develop into a pod holding 10 to 40 seeds. One acre of cabbage seed plants can produce enough seed for 100 acres of eating cabbage.

The highest quality seed to come out of Washington goes to the large-scale commercial farms. The home gardener usually gets the slightly lower quality seed. But that doesn’t matter much, says du Toit. It’s still of good quality. It’s just that they’re likely getting seed that has a 90 percent germination rate instead of 95 percent. With that rate of success, “a home gardener probably won’t complain,” she says.

In 2008, U.S. and European markets saw a surge in seed sales to home gardeners, according to news reports. Whether it’s soaring food prices or the desire to have more control over the quality and safety of their fresh food, American consumers are gardening more.

Now, as winter sets in and the seeds have been harvested from Washington’s valleys, cleaned of weed seed, and treated against disease, it is time to starting planning for next year’s vegetable patch. For home gardeners, du Toit has just a few words of advice. Buy the freshest seed (harvested in 2008) and be sure to store it carefully. While the kitchen is generally too warm, steer clear of the refrigerator because it can be damp. “Seed is a living organism, but it’s in a dormant state. There is a certain degree of respiration or metabolic processes going on,” she says. Heat and humidity will certainly age it. “Consider someplace like the bottom of a closet where it’s cool and dry.”