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University of Minnesota Extension

Strawberry diseases in Minnesota

Key points

  • Good disease management starts with prevention.
  • The early season is important for disease management when key diseases are rapidly reproducing and infecting the blossoms.
  • A variety of organic and conventional fungicides are available for strawberries.

Diseases of strawberries in Minnesota

Long low-tunnels of white plastic, separated by black ground cover, covering rows in a field.
Low tunnels minimize disease in day-neutral strawberries.

The top three strawberry diseases in Minnesota are botrytis, anthracnose and leather rot, as infections can get out of control quickly. Leaf diseases are common but do not frequently impact yield.

Preventing strawberry diseases

Site selection and crop management

Healthy soil is a farmer’s first line of defense against diseases. A soil with enough organic matter can contain numerous organisms such as bacteria, fungi, nematodes, protozoa, arthropods, and earthworms that may suppress soil-borne pathogens.

Well-drained soils are very important to reduce the incidence of soil-borne pathogens such as root rot diseases. 

Variety selection

Many varieties have resistance to certain diseases. Refer to Strawberry varieties for Minnesota and nursery websites for more information on variety selection.

Protected culture

Planting day-neutral strawberries in low tunnels, high tunnels, or caterpillar tunnels greatly reduces disease incidence. Many diseases spread through raindrops, and these structures exclude rainfall. In particular, Botrytis fruit rot is almost nonexistent when rain does not fall on strawberry flowers.

Drip tape irrigation

Using drip tape instead of overhead sprinklers reduces disease. Overhead sprinklers should still be installed for frost protection in the spring, but it is important to be aware that overhead irrigation increases the risk of plant diseases if used for routine watering.

Despite the best efforts to prevent diseases, chances are that some disease will occur in your strawberry fields. Learn to recognize common strawberry disease symptoms, when and how they infect plants, and the weather conditions that encourage them.

Manage disease in the early season

Bloom is an important time to manage strawberry diseases. While we cannot see the disease symptoms during bloom, the fungal spores are actively spreading and infecting the plants and blossoms. The infections that occur during bloom cause symptoms we see later.

Therefore, control diseases at this point in the season to prevent damage later. 

During bloom, apply effective organic or synthetic fungicides from 5-10% bloom until flowers have finished blooming, according to the application intervals on the product labels. Around the Twin Cities, bloom of June-bearing strawberries begins around the third week of May and continues through the harvest season.

Weather impacts fruit disease management

Each pathogen has a range of temperatures and rainfall requirements that promote their infection and spread. However, most of the fruit diseases thrive in warm, humid, rainy conditions. Expect to see more disease pressure during wet years and less disease during dry years.

Powdery mildew is somewhat of an exception; while infection is stimulated by wet weather, repeated subsequent rainfall tends to reduce further spread of the infection on the leaves. Therefore, seasons with wet weather followed by a prolonged dry period may experience more powdery mildew.

Warm temperatures and rain at the onset of bloom stimulate blossom infection of botrytis gray mold and anthracnose. Leaf infection by powdery mildew, leaf spot and other leaf diseases was already occurring prior to bloom but continues during bloom as temperatures become increasingly suitable for infection.

Managing common strawberry diseases


Authors: Annie Klodd, Emily E. Hoover and Emily S. Tepe, Extension educators

Reviewed in 2021

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