WOODBURN, Ore. -- Tulip season needs to be a little warmer.

Barb Iverson, co-owner of Wooden Shoe Tulip Farm, says cold spring weather made for a slow start for the monthlong festival that began March 20 and represents a big chunk of the farm's annual revenue.

"It's been pretty rough," Iverson said the last day of March. "No one's coming out."

But the good news this year is the cold nights and cloudy days also have delayed flower development. So, while attendance has been slow, the flowers weren't really ready to show off, anyway.

Now Iverson hopes that one good blast of warm weather will help the flowers -- and attendance.

"I think people are tired of winter and are biting at the bit to get out," she said.

The Iversons also grow grass seed, wheat, green beans and corn. But the flower business makes up about a third of the Iverson family farm's annual revenue.

Wooden Shoe also sells cut flowers to Safeway and Trader Joe's, and recently started selling to New Seasons Market in Portland. The company, meanwhile, sells its bulbs around the world.

Still, it's the Tulip Fest that generates the bulk of Wooden Shoe's revenue each year.

"The festival is make it or break for Wooden Shoe," Iverson said. "You have to have some nice days to pay the bills."

Cold weather is not the only problem. Four years ago, it rained every day of the festival, cutting attendance to only a fourth of the annual average of 100,000.

This year, despite hail that pummeled parts of the Willamette Valley in late March, there was no significant damage to the flowers, she said.

Then there are the years where the flowers don't cooperate. Nine years ago, she said, the tulips didn't flower until the last week of April.

"We're just hoping we're not going to repeat that," she said.