It’s not every day that a flower supplier on its way out of business offers a farm owner a bargain-basement deal on 35,000 tulip bulbs.

Leslie Dawley and her son Mike took the deal in 2012 and bought the bulbs, but they had no idea what to do with them. They certainly couldn’t pot and sell anywhere near that many. So they borrowed a business model more often used with apples, pumpkins and strawberries: the pick-your-own field.

So many people showed up to wander among the brightly colored flowers and assemble their own bouquets that the Dawleys. owners of Burnside Farms, decided to do it again the next year, even without the great deal on the bulbs. Their tulip festival in Haymarket is now in its third year. And at 150,000 bulbs this year, they now boast one of the largest pick-your-own tulip fields in the nation.

“A lot of it is just for the pictures. If you don’t have 150,000, it’s not going to be a great show,” Mike Dawley said. Only a fraction of the tulips are picked during the festival, which they call “Holland in Haymarket.” It generally lasts three to four weeks, depending on the weather. Last year, 3,500 visitors came to Burnside Farms and picked an average of 10 flowers each.

Visitors pay $3 for a one-day pass, $5 for a season ticket or $6 for a full-season passport with unlimited re-entry for daffodils, tulips and Dutch iris. Tulips are priced at $1 per stem, daffodils at $1 for two stems and Dutch iris at 75 cents per stem.

Stacy Champe of Fort Belvoir and her 2-year-old daughter, Olivia, at Burnside Farms. (Sarah Lane/The Washington Post)

Burnside Farms plants 200 different varieties, from extravagantly petaled peony tulips to crinkled and curling parrot tulips to fringed crispa tulips. At least five new types bloom every day. “You can come almost every day and have an entirely different show,” Mike Dawley said.

Debra Longmire of Fairfax Station came April 17, the day after the farm opened for tulip season, and returned with her next-door neighbor last week. “There’s such a big change in one week,” she said, and marveled at the fact that the field was still only about 35 percent in bloom, though it seemed to be dotted everywhere in color. Longmire said she was thinking of returning a week later, when the field would be close to peak bloom, and she would definitely return for the farm’s pick-your-own iris and sunflower festivals this month and in July.

On a chilly but bright afternoon last week, couples strolled through the fields arm-in-arm with baskets of fresh-picked tulips and daffodils. Parents took pictures of their children surrounded by the vibrant blooms and children squealed at the turkeys, goats, pigs, and baby chicks at the farm.

The Dawleys have owned the farm at the western end of Prince William County since 1995. For most of those years, they grew flowers in order to sell them in Leslie Dawley’s flower shop. After she lost the lease on her store in McLean, they started growing flowers for wholesale. The family still sells some flowers, including zinnias and cockscombs on that basis. But the pick-your-own fairs have become their primary business.

The Prince William County Department of Economic Development said it does not track pick-your-own farms, but in neighboring Loudoun County, agricultural affairs expert Cassie Walls said that pick-your-own flowers is a rare business model.

“The majority of our farms that have flowers still are selling wholesale,” Walls said. “I think there’s more of a demand for the fruits and vegetables [as a pick-your-own crop]. The consumer will come and pick more of the vegetables and fruits than they will of the flowers.”

The Dawleys said they make the business work in part by keeping labor costs low — they hire a few seasonal employees for tasks like manning the ticket booth and gift stand — but they do all the planting themselves.

One farm — Holland America Flower Gardens in Washington state — planted twice as many bulbs for its pick-your-own field this year. But few, if any, others in the United States outrank Burnside Farms.

Leslie Dawley picked a few flowers, showing off the variety in their color and shapes. She and her son could plant fewer bulbs, she said, but the point of “Holland in Haymarket” is the extravagance and expanse of the field.

“If we don’t have the show,” she said, “it doesn’t make it a wonderful event.”