NEW YORK -- High prices at the pump and the produce aisle have sent home gardeners into their yards with a mission: Grow-it-yourself dining. Sales of vegetable seeds, tomato transplants and fruit trees are soaring as enterprising planters grow their own food.

W. Atlee Burpee -- Co., the nation's largest seed company, has sold twice as many seeds this year as it did last year, with half the increase from new customers, the company's president, George Ball, estimates.

"When we saw the gas prices go up, we said, 'Oh boy,'" Ball said.

Interest in growing fruits and vegetables picks up during economic downturns, people in the industry say. Seed companies say a dime spent on seeds yields about $1 worth of produce. Bad economic times also can mean more time to garden -- people who cancel their summer vacations are around to water their tomatoes. The housing crunch also works in favor of vegetable gardens: If you can't sell your home, you can replant it.

"Over the past year or two when my boyfriend and I went shopping and started seeing how little we got out of the grocery store for how much, we figured we might as well give it a shot trying our own veggies and take some of the weight off our pockets," said Janet Bedell, who works at a lawn and garden center in Venice, Fla.

That kind of thinking is leading to a big year for companies that sell to fruit and vegetable gardeners. Seed Savers Exchange, a nonprofit dedicated to preserving heirloom vegetables, ran out of potatoes this year and mailed 10,000 tomato and pepper transplants to customers in early May, double its usual amount. The organization, based near Decorah, Iowa, sold 34,000 packets of seed in the first third of this year, more than it did all last year.

Stark Brothers Nurseries and Orchards Co., a fruit-tree nursery based in Louisiana, Mo., has been so busy that "we've had our phones completely staffed and staffed overtime for the past two months," said Lita Eatock, marketing manager.

"A lot of wholesalers are really sold out of things," said Michael McConkey, owner of Edible Landscaping, a fruit-tree nursery and Web site based in Afton, Va. "I was attempting to get some apple rootstock to graft onto some apples and I really had to work to find some."

The learning curve for home gardeners can be steep. Janet Bedell in Florida said her first fights were with bugs and fungus; now she's working on keeping birds and squirrels away.

While some vegetables, like salad greens, are nearly effortless, others, like celery, present a challenge. New gardeners often don't know what it takes for a plant to survive, said Ryan Schmitt, greenhouse manager at The Flower Bin in Longmont, Colo. "It's not a sculpture. Most people get the water thing, but sun and food, they often forget."

New vegetable gardeners are packing classes from Skillins Greenhouses in Falmouth, Maine to Love Apple Farm in Ben Lomond, Calif.

"If I think of a name of a class, I'll give it and people will come," said Cynthia Sandberg, owner of Love Apple Farm. "People will drive three hours for these classes. It's not because of me, it's because they want to learn."

Burpee's eight-person horticulturist hotline at the company's Warminster, Penn., headquarters has been overwhelmed with calls from gardeners trying to learn the basics of soil acidity and seed starting. Absolute beginners visiting nurseries occasionally ask questions like, "Oh, tomatoes are a plant?" said Schmitt at the Flower Bin. "That's usually followed by, 'Oh, I can grow that?"'

"It's a teaching moment," Schmitt said. "I can fill them with the right information."

GRDN, a shop in the New York City borough of Brooklyn, is getting a lot of questions about which edible plants can be grown on a fire escape, said staffer Cindy Birkhead. "There's lots of interest in herbs, blueberry bushes, tomato plants, any transplants or shrubs that bear edible fruit."