Have you thought about growing strawberries but don't want to commit to a perennial crop? Are you discouraged by the short 3-week harvest season of most strawberries? Try day-neutral strawberries, an annual crop that keeps producing sweet, flavorful berries from late June to mid-fall.
Unlike June-bearing strawberries that produce a burst of fruit for 3 to 4 weeks starting in mid-late June, day-neutral strawberries continue producing new flowers and fruit throughout the season. They will produce fruit as long as temperatures stay between 40 and 90 degrees F, with production tapering off toward the end of the season.
Unlike June-bearing strawberries, day-neutral varieties are meant to be grown as annuals, meaning they are re-planted each year just like vegetable plants. For vegetable gardeners, container gardeners, or those renting community plots, this is a good thing.
How do day-neutrals compare to June-bearing strawberries in terms of yield and flavor?
Day-neutral strawberries typically produce more berries than June-bearing strawberries. University of Minnesota research published in 2016 found that six day-neutral varieties yielded consistently higher than June-bearing strawberries over the season, and added 14 weeks of production.
Growers of day-neutrals may expect between one-half to one pound of fruit per plant over the whole season. However, lower yields can occur, particularly for gardeners new to this crop.
In terms of flavor, each variety is different. Fortunately, there are many tasty options for day-neutral varieties. In comparisons of day-neutral varieties suited for Minnesota, data from the UMN West Central Research and Outreach Center found that on average, they were just as sweet or sweeter than June-bearing strawberries.
Selecting a variety
Recommended varieties for Minnesota, tested on multiple sites in multiple years, include: Albion, Evie-2 (Evie-II), Monterey, Portola, San Andreas, and Seascape.
San Andreas and Albion were found to be the sweetest in UMN research. Portola had the highest yields but was the least sweet of the six varieties tested. However, all varieties tested are relatively sweet.
How many plants to grow
The number of plants to grow depends on how many berries you can eat, and how much space you have in your garden. I plan to grow them in a 6- by 4-foot raised bed in 2020, in which I can fit exactly 12 plants.
However, most nurseries with online ordering tend to sell day-neutrals in packs of 25 bare-root plants. If each plant produces one pound of fruit, 25 plants would produce 25 pounds of fruit under ideal growing conditions. Realistic yields may be slightly less when factoring in normal stresses of Minnesota gardens (rabbits, deer, insects, diseases, soil problems).
Assuming your plants produce fruit from June 29, 2020 until October 18, 2020 (16 weeks) it would be reasonable to expect 1.0-1.5 pound of fruit per week if you purchase 25 plants, with yields decreasing after mid-August. If that sounds like too much fruit, consider splitting a plant order with a fellow gardener like I am.
Caring for your day-neutral strawberries
Grow day-neutral strawberries on landscape fabric, white or black plastic, or straw. UMN researchers found that growing day-neutral strawberries on raised rows with black plastic achieved higher yields and larger berries than when planted on straw mulch.
While gardeners are welcome to replicate the plastic matted row setup used by commercial growers, a more feasible substitute may be landscape fabric. I do not recommend growing strawberries directly on soil, in order to keep the berries clean and reduce disease.
Commercial growers usually grow day-neutrals under clear plastic "low tunnels" to further extend the growing season, but this is an optional step. This setup may keep out deer, but will not prevent small mammals or insects pests unless it is very well sealed on all sides.
Since the berries touch the ground while growing, it is especially important to plant strawberries in an area with good drainage that does not flood. Growing in raised beds or containers helps with water drainage in wet areas.
Plants should be spaced no closer than one foot apart on each side. Therefore, a 6- by 4-foot raised bed can comfortably fit two or three rows, each containing six plants. Planting too closely can cause smaller berries, soil nutrient stress and lower yield per plant.
Removing flowers and runners:
Blossoms should be removed from the plants for about the first four weeks after planting, or until late June. After that point, stop removing the flowers and allow the fruit to form. Runners are not needed, and they take energy away from fruit production. So remove runners as needed.
For more information on growing strawberries, see Growing strawberries in the home garden.
Petran, A. et al. 2016. Yield and quality characteristics of day-neutral strawberry in the United States Upper Midwest using organic practices. Biological Agriculture and Horticulture 33(2).
Poppe, Steve and Esther Jordan. 2014. "Taste of sweet success: Strawberry season extended using low-tunnel production." Organic Broadcaster, March/April 2014. Midwest Organic & Sustainable Education Service (MOSES). https://mosesorganic.org/farming/farming-topics/market/strawberry-season-extended/