Coloma Farms marks a century of Wisconsin potatoes on 2,700 acres

Wisconsin growers produced 28.8 million hundredweight of potatoes in 2025 — third nationally — and a $466 million crop harvested across 68,000 acres, according to the National Agricultural Statistics Service. One Waushara County operation has been part of that output for nearly a hundred years, and this season it landed squarely on average.

Coloma Farms, run by Steve Diercks, 78, and his son Andy, 55, reported yields of about 300 cwt per acre on the early crop and 450 to 500 cwt per acre on full-season potatoes in 2026. Steve called the year "about average." Prices improved. "The 2026 potato price was a bit better than in 2025," Andy said — though he conceded that bar was low, because the 2025 price was "terrible."

What does a century of potatoes look like?

The family started growing fresh and seed potatoes in Langlade County in the 1930s. In 1962 they split the operation, and Robert Diercks and his son Steve established the Coloma farm about 4 miles west of the village. Seed potatoes still came from Langlade for years.

The move south wasn't sentiment. "My dad had a good friend who was superintendent of the Hancock research station," Steve said. "They decided to come down this way because they could get the potato crop in 30 days ahead of the crop in Langlade County."

Today the farm owns 2,700 contiguous acres in Waushara and Adams counties, in the heart of the Central Sands, with roughly 850 acres planted to potatoes each year on a three-year rotation mixing corn, soybeans and canning crops. Everything is irrigated. Russets, reds, whites and yellows go out through a broker, plus a fresh-packing shed supplying grocery stores directly — with on-farm storage that holds potatoes for nearly a year, giving buyers a consistent 12-month supply.

Water and drainage drive the system

"Potatoes don't like to have wet feet," Steve said, explaining why the region's sandy soils work: well-drained ground prevents crop problems when rain lingers. Irrigation pivots generally cover about 160 acres each, with one watering up to 200.

The water picture has shifted in a decade. "We're much better at using water than we were years ago," Steve said. "Water quality is a bigger problem than water quantity. Ten years ago, everyone was worried about whether the wells were going to go dry, but the water table here hasn't changed. It's not like Nebraska and Colorado where it keeps falling. We measure our wells to see how they're doing."

The Dierckses collaborate with University of Wisconsin-Madison researchers on farmwide water efficiency, host field trials, and keep a UW-maintained observation facility on the property. "No one else in the country has the potato research team that we have here in Wisconsin," Andy said.

Labor, logistics and harvest mechanics

Planting starts around April 10, weather permitting, and wraps the first week of May; harvest runs early August to early October — a window Andy says has stretched because cold weather now arrives later. A windrower digs potatoes ahead of the harvester, and on a good day the farm clears about 40 acres. It employs nine people year-round, doubling during packing season. A trucking firm hauls most potatoes; buyers send their own trucks for fresh product. "We don't want to be in the trucking business," Steve said.

Technology has moved unevenly. Drones now spray some fields and packing equipment "has gotten much more automated," Steve said, "but our harvesting equipment is much the same as it has been." The farm also grows "little potatoes" for The Little Potato Co. of DeForest, which required retrofitting equipment for the smaller spuds.

Four generations of leadership

Andy's 2002 election as president of the Wisconsin Potato and Vegetable Growers Association made him the fourth Diercks generation in that role: Ben was the WPVGA's first president, 1948-49; Robert led it in 1975-76; Steve in 1989. Andy now represents District 2 on the Wisconsin Potato Industry Board and spent 13 years on the DATCP board, several as chairman. Steve sits on the state's Groundwater Coordinating Council.

Steve passed the Coloma Farms presidency to Andy several years ago and serves as vice president. "I'll probably keep doing this until they kick me out," he said. With 2026 prices recovering from a dismal 2025 and the water table holding, the family's fifth decade of leadership looks set to build on stable ground.