"Anything that's ugly or weird or unusual, it just sells like crazy," said Randy Graham, who grows 40 pumpkin varieties near Champaign, Ill.
At least in part, the market shift reflects the commercial growth of Halloween, and the fall season surrounding it, farmers and others said. Popular arbiters of home style such as Martha Stewart regularly talk up unusual pumpkins on television and the Internet.
And, U.S. farmers are growing hundreds of unusual varieties to satisfy consumers' desire for something new, plant breeder Jamie Hoffman said.
"We put a fair amount of effort into pumpkins that are not round and orange, something that's different," said Hoffman, who owns Outstanding Seed Company in Monaca, Pa. "Sometimes we get surprises — pumpkins that are multicolored and warted."
The National Retail Federation estimates 68.5 million Americans will buy a pumpkin to carve this year, an increase of 5 percent in the past five years. In all, Americans will spend $1.63 billion on Halloween decorations, although it's unclear how much of that money will go toward odd pumpkins.
But those who do spend have plenty of choices.
Many of the unusual pumpkins are hybrids — combinations of other, existing varieties. But some farmers have begun growing heirloom varieties that buyers from a century ago might recognize, such as blue-green Jarrahdales from Australia and the reddish, flat-bodied Rouge Vif d'Etampes.
There are also specially bred varieties the like warty Knucklehead. Hoffman pointed out a deep irony in their popularity.
Warts are a dominant trait and, if pumpkins or their cousins the squash are left to breed on their own, warts will likely develop. Although they're harmless, Hoffman said breeders have long fought warts because they turned off customers.
"Plant breeders worked feverishly over the last 50 years to get rid of warts," he said.
Now, breeders and farmers look at the lumpy disfigurations a little differently.
"Something unusual for Halloween, that maybe had warts and stripes — that'd be pretty cool," Hoffman said.
Pumpkin breeding is done by hand, with breeders using pollen from one variety to pollinate another, he said. Most have a good idea of what they're shooting for and, in general, what they'll get based on the pumpkins they're working with.
Hoffman, who opened his company six years ago, said he once dreamed of selling seeds for his hybrids at $25 a pound. Now, growers pay up to $200 a pound for something good, he said.
Graham, the Illinois farmer, said that reflects consumers' willingness to pay more. When he was a child, pumpkins were an inexpensive tradition.
"You went to the grocery store and each child got a pumpkin — you carved it, you went trick or treating and that was that," he said.
But in the past decade, he's seen people spend $50 or more on pumpkins and other Halloween decorations.
John Ackerman grows 150 pumpkin varieties on his farm near Morton, a central Illinois community that bills itself as the pumpkin capital of the world. Libby, the brand that accounts for about 85 percent of the canned pumpkin sold in the U.S., grows all of its pumpkins around Morton.
Ackerman started out part-time, growing big, beige Dickinson pumpkins for Libby to can. But in 1998, he grabbed a hundred or so that had grown too far down in a creek bed for mechanized pickers to reach and set them out in his yard.
"Amazingly, people started to stop and ask, 'Are those for sale?'" he said. "I think my reaction was, 'By golly, they are for sale.'"
He's now a full-time farmer growing pumpkin varieties from all over the world.
"I'm always looking for that next, neat thing," Ackerman said. "Some of them are long and tall, some are deeply ribbed, some have (thick stem) handles."
But not all the new varieties make for good eating, and Ackerman said he still has a soft spot for the pumpkins that got him into the business.
"That common old, beige-looking Dickinson pumpkin makes a pretty good pie," he said.