Growing strawberries in Wisconsin is challenging due to the short season and harsh, unpredictable winters. Success requires specific protective measures and localized knowledge. A successful patch demands careful planning, from selecting the right variety to providing diligent year-round care, but the sweet flavor of homegrown berries makes the effort worthwhile.
Selecting the Right Variety and Location
Choosing a cold-hardy cultivar is the most important step for success in Wisconsin’s climate. Most growers select June-bearing varieties, which produce a single, large crop over two to three weeks in early summer, ideal for preserving and freezing. Recommended cold-tolerant June-bearers include ‘Honeoye,’ known for its high yield and firm fruit, and ‘Sparkle,’ a late-season variety prized for its excellent freezing quality and hardiness.
For a longer, continuous supply of fresh fruit, Everbearing or Day-neutral varieties, such as ‘Ozark Beauty,’ offer smaller yields throughout the growing season until the first heavy frost. These types require more intensive management and are less cold-hardy than June-bearers, making them less common for large-scale production. All strawberries thrive in a location that receives a minimum of six to ten hours of direct sunlight each day.
Soil composition and pH level are equally important for healthy plant establishment. Strawberries perform best in well-draining, loamy soil enriched with organic matter, due to their relatively shallow root systems. The optimal soil pH for nutrient availability is slightly acidic, ranging between 5.5 and 6.5. Conduct a soil test at least a year before planting to allow enough time to amend the pH with lime or sulfur as necessary.
Planting Techniques and Timing
Planting should occur in early spring as soon as the soil is dry enough to be worked, typically around late April or early May in Wisconsin. Bare-root plants should be soaked in water for up to an hour immediately before planting to ensure they are fully hydrated. Dig a hole deep and wide enough to accommodate the entire root system without bending the roots upward.
Proper crown placement is fundamental for the plant’s survival and future productivity. The crown, the central part from which leaves and roots emerge, must be set so that its midpoint is perfectly level with the soil surface. Planting too deep will smother the crown, while planting too shallow will expose the upper roots to drying out. After planting, firm the soil around the roots to eliminate air pockets and water thoroughly.
The two main spacing methods are the matted row system, common for June-bearers, and the hill system, suited for Everbearing and Day-neutral types. In the matted row, plants are spaced 18 to 24 inches apart in rows three to four feet apart, allowing runners to fill in a narrow 18-inch row. The hill system involves closer spacing, often 12 to 18 inches apart, and requires removing all runners to encourage the mother plant to focus energy on fruit production.
Year-Round Maintenance and Winter Protection
Routine summer care focuses on establishing a strong root system in the first year to ensure a productive harvest in the second season. Consistent moisture is necessary, as strawberries have shallow roots, requiring about one inch of water per week. Weeds are a significant competitor for water and nutrients, making shallow cultivation and hand weeding necessary to prevent damage to the delicate surface roots.
For June-bearing varieties in their first year, all flower blossoms should be removed to redirect the plant’s energy into developing a robust crown and root system. This practice, known as de-blossoming, is crucial for maximizing the following year’s yield, as first-year fruit production weakens young plants. Runners should be trained to root within the designated row width to establish the matted bed, removing excessive runners to prevent overcrowding.
Winter protection is the most important factor for perennial strawberry survival in Wisconsin’s cold climate, as crowns sustain damage below 18°F. The protective mulch, ideally clean wheat or rye straw, must be applied only after the plants have gone dormant and the ground has frozen to about a half-inch deep, usually in late November or early December. Applying mulch too early can cause the plants to smother or fail to harden off properly.
A thick layer of loose straw, approximately four to six inches deep, is needed to insulate the crowns and prevent damage from alternating freezing and thawing cycles. This insulating layer helps maintain a stable crown temperature, which is essential for survival. In the spring, when new growth emerges, the majority of the mulch should be raked off the rows and into the aisles. There, it will continue to suppress weeds and keep the developing fruit clean.
Harvesting and Post-Harvest Bed Renewal
Strawberries are ready for harvest when they are fully colored, firm, and easily detach from the plant. The best technique is to pick the fruit with a small piece of the stem still attached, which prolongs the berry’s shelf life. Harvesting occurs daily or every other day during the peak season, which lasts about three weeks for June-bearing types.
Immediately following the final harvest, typically in July, bed renovation must begin to ensure a strong crop the following year. The first step involves mowing the old foliage one to two inches above the crowns, taking care not to damage the plant’s growing point. Removing the old leaves helps control diseases and stimulates new, vigorous growth.
Next, the matted rows must be narrowed to 8 to 12 inches wide by cultivating or tilling the aisles between the rows. This practice removes older, less productive plants and concentrates new, vigorous plants along the row edges, where most fruit is produced. Fertilization immediately follows renovation, using a balanced fertilizer like 10-10-10 or a nitrogen-only source to support the development of new leaves and the flower buds for the next season’s crop.