In a typical year, potato growers who start digging their crop too soon give up some of their potential yield by harvesting immature spuds. But growers who wait this year may miss out on unheard-of prices.

“There are guys killing russets now,” Mike Carter, chief executive officer of Rosholt, Wis.-based Bushmans’ Inc., said July 30 of the step growers take before harvesting that sets the spuds’ skin.

Some Wisconsin growers are killing potato plants — a process that diverts the plant’s energy to growing the potatoes.

“Digging early sacrifices yield, but the market is high enough that they’re starting now anyway. It’s not a full-blown harvest, but some of our partners should be ready soon.”

The U.S. Department of Agriculture did not have a price for Wisconsin potatoes available in its July 30 report, but the same day Bob Johnson, sales manager for Katz Produce Sales, Plover, Wis., said 50-pound bags of size B reds were going for as much as $27-29 in Wisconsin.

“I’ve never seen prices this high before,” he said. “It’s not unusual at this time of year to see $10-15 on Bs, but I’ve never seen $29 before.”

Johnson said there soon would be more reds available from Wisconsin, but there also were areas like North Carolina and Southern California that were finishing up their seasons. Furthermore, sizes in Wisconsin likely will be getting bigger as harvest progresses, which means less Bs.

“The market for Bs could actually be higher 10 days from now,” he said. “Prices are high and changing by the hour. It’s the craziest potato market I’ve ever seen.”

Wisconsin had a bumper 2012 potato crop, but the state’s storage supplies were depleted sooner than usual. Johnson said Katz typically has storage spuds into the third week in July but this year ran out during the first week of the month.

“There’s extremely short supply nationwide,” he said. “The storage crop cleaned up a lot faster than everyone expected, and the new crop is late in multiple growing areas.”

Nebraska, Oregon and Washington — like Wisconsin — all got late starts. Making matters worse, California growers significantly reduced russet acreage.

“When they were ready to plant in January, the market was in the toilet,” Johnson said of California. “They opted not to spend a lot of money planting potatoes, and they planted cotton or other things instead. They’re normally done around the end of July, but they were done two weeks ago.”

Rick Kantner, director of sales and marketing for Alsum Farms & Produce, Friesland, Wis., said markets will maintain significantly high prices until supplies increase, likely in early September. Although high prices can be good for growers, there are limits, he said.

“It’s a delicate balance,” Kantner said. “If prices go too high, consumers might back away. That leads to price decline and oversupply.”

Kantner said his company expected to start digging reds by Aug. 2 with russets to follow two weeks later.