Giant pumpkins break world records and confound scientists and growers alike

Farm Forum

If a world-record pumpkin turns up at the Stillwater Harvest Fest’s weigh-off this year, it won’t surprise gardener Chris Stevens.

His behind-the-scenes view of competitive pumpkin growing has him predicting a windfall of new records this year. Just like most every other year for the past three decades.

“It is very puzzling,” said Stevens of New Richmond, Wis. “We hit 1,000 [pounds, in 1998] and people thought, ‘When is it going to end?’ It surprises us every year to see it go up another 100 pounds.”

In a streak that’s taken on a freakish life of its own, pumpkin growers this fall will turn in a crop of giants that many expect to be the heaviest ever seen anywhere.

It will take a pumpkin weighing at least 1 ton, the weight of a small car, to challenge the 2,032-pound goliath seen last year at a contest in Napa, Calif.

If history is any indication, someone will beat it: Since 1985 there have been just six years when the world record hasn’t fallen.

“It’s really amazing to us growers how this is happening,” said Lorelee Zywiec, a gardener who’s chasing the world record on a patch of ground that was once a western Wisconsin dairy farm. As of last week, she has one that she estimates at 1,600 pounds.

There’s no secret to growing it, said Zywiec. “You’ve got to put hard work in,” she said. Soil tests, careful monitoring of the weather and constant vigilance against mice and deer are just the basics. She also waters her plants by hand to ensure even watering. That can take up to 45 minutes per plant. Even a bountiful season can end in disaster if cucumber beetles, squash bugs or vine borers show up — “the kiss of death,” said Zywiec.

Vegetable ‘rocket scientists’

Competitive pumpkin growers are like “the rocket scientists of the vegetable world,” said author Susan Warren, whose book “Backyard Giants” documented two farmers’ attempts in 2006 to grow a record pumpkin. “They are delving into everything from plant genetics to soil microbiology.”

Like farmers before them who developed today’s tomato plants, pumpkin growers use genetics and crossbreeding to develop the plant with the most desirable traits. The Internet allows the diffuse world of pumpkin growers to gather at one spot online ( to share seeds and secrets. Growers keep diaries and post pictures of their successes and failures.

After following the farmers through a full season of backbreaking work, Warren said she walked away inspired.

“It’s like fairy-tale land, these pumpkin patches. You just expect Cinderella’s carriage to pull up.”

Alex Bogie said giant pumpkins captured his imagination at a young age, when he read what many consider the grower’s bible: “How to Grow World Class Giant Pumpkins,” by Don Langevin. (A testament to the passion of pumpkin growers: A used copy of the out-of-print book sells for $43 on Amazon.)

Bogie used to farm in north Minneapolis, but the giant in his tilled-up back yard drew so much attention he found it hard to do much gardening.

“Everyone was stopping by,” he said. “You couldn’t get a free moment to work.” He took to wearing headphones and pretending he couldn’t hear people shouting out questions, but then they would rattle the fence to get his attention.

He moved recently to Ham Lake, drawn by the prospect of a 2-acre lot, black soil, full sun and seclusion. He sent core samples of his back-yard soil to an Illinois laboratory for analysis of the micro- and macronutrients already in the ground. He chose seeds from previous prizewinners. And to fight off the deer, he installed a tall fence around his plot.

He planted seeds indoors April 10, moved them to a greenhouse 10 days later and carefully tended the emerging vine. Today that vine is as thick as a rope and winds 100 feet back and forth across a patch of his garden. Leaves 2 feet across stand in neat rows that point to the center of the plant, where one absurdly large pumpkin sits on the ground. Bogie said it grew at a rate of 52 pounds a day at one point this season, a growth rate he’s never seen.

One of his prize-worthy pumpkins grew so fast that it developed a crack near the stem, a defect that can lead to disqualification. Any splits, holes or soft spots can mean rejection.

Crestfallen, Bogie filled the crack with expanding foam and let the pumpkin grow. If it gets large enough, the seeds might be valuable for next year, he said.

“Some seeds will go for $400 to $500, but it makes sense with $5,000 prizes for the largest pumpkin,” he said.

Bogie had another brush with disaster recently: An electric thermometer he installed to warn him of freezing temperatures went off a few weeks ago.

Bogie leapt into action. He turned on an overhead sprayer, left it on overnight and in the morning was greeted with pumpkin plants caked in a thin layer of ice, but still alive.

Elsewhere in the garden, the carnage was huge: Tomatoes, peppers and beans were done in.

Still a mystery

A University of Minnesota plant expert said that whatever’s happening in the pumpkin patches to make pumpkins get so big, it still hasn’t been fully explained by science.

Some of it, like genetics and good nutrition, is understood, said University of Minnesota plant expert Cindy Tong. But there’s a lot that’s not known, too. Microbial activity, helpful fungi, nuances of the relationship between genetics and the environment — the answer could be anywhere.

“We don’t know a heck of a lot,” said Tong. “People don’t like hearing that.”

The mysteries of how to coax a giant pumpkin from the earth drive growers like Zywiec. Relying on a network of other growers and her own years of experience, she’s put all of her energy this year into her pumpkin patch. She even chose a mate for her pumpkin plant, cutting a male flower from another gardener’s pumpkin vine to mate with the female flower on her plants.

Her choice of a mate for her plants came from a plant that grew a 2,328-pound pumpkin last year in Switzerland. That one didn’t set a world record because of a hole, but it raised the likelihood of another record-beater this year.

Zywiec, who someday soon will pull the pumpkin from her garden and haul it to Stillwater on a trailer behind her Dodge Dakota pickup, hopes it comes from her garden.

“I’d be just tickled darn pink,” she said.