The science of Minnesota strawberries

An image of a bunch of equally spaced strawberries agains a gold backdrop

When it comes to fruit research, the University of Minnesota is best known for developing the Honeycrisp apple. However, the College of Food, Agricultural and Natural Resource Sciences' (CFANS) Department of Horticultural Science has a rich history of research into other fruits and berries, including apricots, plums, grapes, raspberries, currants, and strawberries. The strawberry research program has been particularly active, not only in creating new varieties, but also in the study of production practices that make this crop more resilient and profitable for growers.

Today, after more than 50 years of continuous study, U of M experts have developed strawberry varieties that thrive in the face of Minnesota’s challenging climatic conditions. Strawberries are the fifth most popular fruit in the U.S., and Minnesotans have a strong affinity for them.

Strawberries in Minnesota

The Minnesota growing season is generally characterized by short summers and long winters. But that doesn’t mean strawberries can’t succeed in the state. As climate change increasingly takes effect, it is becoming increasingly important to understand how our crops will be affected.

“Adapting to a changing environment is essential for ensuring the success of our strawberry research,” says Jim Luby, professor in the Department of Horticultural Science. “After 50 years of trial and error, our dedication to intensive research has provided us with the knowledge necessary to keep our strawberry production flourishing for years to come.”

The U of M has conducted studies on two strawberry types over the years. June-bearing varieties are planted in the spring and can be harvested the following year beginning in mid-June, but are usually done producing fruit by early July. Day-neutral strawberries are also planted in spring and bear fruit from July through October of the same year, or until the first killing frost. June-bearing varieties overwinter, while day-neutrals are best grown as an annual in Minnesota’s climate.

Luby—with Emily Hoover, professor and head of the Department of Horticultural Science, and Nate Dalman and Steve Poppe of the U of M’s West Central Research and Outreach Center (WCROC) in Morris—examine how well newly released strawberry cultivars and top picks from the University’s breeding program adapt to Minnesota’s environment. Since 1982, the WCROC has been conducting ongoing studies on various varieties of strawberries.

Some growing challenges

To determine the best method for growing strawberries, researchers have investigated a range of cultivars and growing systems including low-tunnels and soilless gutters, as well as mulch and plasticulture systems. Low tunnels are used in agriculture to protect crops from adverse weather conditions and extend the growing season. In strawberry production, they are typically made of a series of hoops, covered with a protective material. Plasticulture systems are agricultural production practices that use plastic materials to improve crop production.

The WCROC started experimenting with the use of low tunnels on day-neutral strawberry cultivars in 2013. The study looked at how the tunnels extended the strawberry growth season by providing a mini-greenhouse environment above each strawberry row. When the outdoor temperature drops, the low-tunnel can provide a warming effect for the plants. The tunnels also protect the plants from hail and wind damage.

Sustainable sweetness

It’s clear that strawberries will continue to be a popular part of diets in the United States. U.S. Department of Agriculture statistics show the country produced nearly 1.34 million tons of strawberries in 2021, and according to the Minnesota Department of Agriculture, there are more than 90 strawberry farmers right here in the state.

Andy Petran, who pursued his PhD with Hoover at CFANS and is now a strawberry grower at Twin Cities Berry Co. in Farmington, MN, is confident in the future for farmers of this beloved berry. “I believe that through careful research and trial, we can make farming more accessible by protecting our crops and expanding our growing seasons,” says Petran. “It’s an investment in all of our futures and the future of farming in Minnesota.”