The Northwest Flower &Garden Show, a 21-year-old tradition once thought dead for a lack of a buyer, has sold.

Seattle-based show owner Duane Kelly said he received two serious offers, including one from a nonprofit horticultural organization and the other from an experienced show producer.

“I chose the latter,” he said. “I have accepted a firm offer and the buyer is in the due diligence phase.”

Kelly, who is leaving the garden show business to pursue his career as a playwright, said he will not publicly identify the buyer until the sale closes later this month.

Though Kelly had long ago booked space at the Washington State Convention &Trade Center for the show from Feb. 3 to 7, 2010, nursery owners and regular show participants have been anxiously awaiting news of a sale for months.

Planning of the 25 or more large-scale display gardens at the annual event is a process that typically starts in March, almost immediately after the February show.

John Christianson of Christianson’s Nursery in Mount Vernon said his business had hoped to do a display garden in 2010 and still wants to do so, despite the time crunch.

“I would be thrilled if there was a flower and garden show in 2010,” he said. “We’re still interested in doing a garden, but, boy, we’d certainly need lots of encouragement and information.”

Christianson said Kelly and his staff’s support of the display garden creators is part of what made the show, which also includes about 300 retail vendors, exceptional.

“They recognized that gardens were the show,” Christianson said.

He hopes the new owners will do the same. Quickly.

Kelly put his Seattle company, Salmon Bay Events, which also runs the San Francisco Flower &Garden Show, up for sale in October 2008.

In February 2009, when a sale wasn’t forthcoming, he said both the company’s shows would wither and die if buyers did not come forward.

He said then that the asking price for both shows, if sold as a package, would be between $1 million and $2 million.

The sale of the San Francisco Flower &Garden Show closed in late May with San Francisco Garden Show LLC, a group that formed to purchase the event.

Kelly did not disclose the sale price of that show or the Seattle-based show, but said the Northwest Flower &Garden Show, the larger of the two, is worth more.

Salmon Bay Events’ garden shows are the second- and third-largest in the country, following only the Philadelphia Flower Show.

Watch the show’s official Web site for updates.