Article written by Madeline Wimmer, UMN Extension Fruit Production Educator.
General Fruit
Webinar recording: SARE labor training, “Creating systems to mitigate on farm conflict”
UMN Extension Fruit Crop Reporting Tool
Apples
Growth stage and pest management update: Apples between 18-30mm
Grapes
Growth stage update: Early bloom
Nitrogen application recommendations around bloom
Article and video: Petiole sampling for grapes
Sucker and watersprout management
Blueberries
Growth stage update: Early green fruit set
Honeyberries/haskap
Growth stage update: Nearing harvest
Day-neutral Strawberries
Growth stage update: Fruit set
General Fruit
Webinar recording: SARE labor training, “Creating systems to mitigate on farm conflict”
This past February, SARE (Sustainable Agriculture Research and Education) offered a labor training program to Minnesota and adjacent states. This program covered a variety of topics on Minnesota paid leave, strengthening human resources (HR) at the farm, training on the H2A program, budgeting for labor costs, and mitigating on-farm conflict. Recordings of the program were shared with registrants, and the mitigating on-farm conflict webinar has been posted to the UMN Small Farms YouTube channel for public viewing. Below is a link to the recorded webinar.
To watch the recorded webinar, check out the link below…
Creating systems to mitigate on farm conflict
UMN Extension Fruit Crop Reporting Tool
Interested in sharing anything about the fruit crops on your farm? Feel free to share observations about diseases, pest management, or other production aspects using our new UMN Extension Fruit Crop Observation Report tool. If you have a question you want addressed in a future update article, you can include that in your report.
Apples
Growth stage and pest management update: Apples between 18-30mm (Zestar! at 30mm)
Images: Apples varieties nearly four weeks after bloom: Honeycrisp (21mm; upper left), Gala (18mm; upper right), First Kiss (18mm; lower left), McIntosh (20-24mm; lower right). Photos taken at Sekapp Orchard in Rochester, MN, on 06/03/2026.
It’s been nearly four weeks after full bloom for most apple varieties in Southeast Minnesota and apples are continuing to enlarge as terminal shoot growth reaches between 6-11 inches for most varieties, and shoots begin to lignify making them more difficult to remove by hand.
Disease Management
Petal fall happened at this specific orchard around 05/14/2026 this year, which places the current stage for pest management around third cover where growers need to be aware of limitations based on pre-harvest intervals for certain products used. For information about disease management during this stage, refer to, “Apple Third and Summer Covers - Diseases” in the Midwest Fruit Pest Management Guide starting on page 37.
Apple maggot
Map: This degree day model map was created by Anthony Hanson and can help growers estimate adult emergence for apple maggot.
Since the USDA apple maggot tracking map has been offline, Anthony Hanson, UMN Extension Integrated Pest Management Educator, has created his own maps that track degree days relevant to apple maggot emergence. Anthony’s model is based on the Laing and Heraty model of 1984, which uses a modified sine-wave model with a base threshold of 47.7 F, starting on March 1st.
When used with trapping, this can help growers estimate adult emergence this year (rather than a replacement for trapping). Right now is a good time for growers in Southern Minnesota to deploy traps, while growers in central Minnesota can deploy soon, and northern growers still have more time before adult emergence is expected.
Grapes
Growth stage update: Early bloom
Image: A newly trained vine with a cluster showing is beginning to bloom. This cluster is typically removed to allow for the vine to allocate more energy into establishment than fruiting in this stage of training.
Grapes are beginning to bloom in southern Minnesota. Bloom is a critical period for managing diseases like black rot, downy mildew, and powdery mildew keeping in mind that grape rachises (where the berries attach to the cluster) and leaves will remain susceptible to various diseases even as the grapes become more resistant as they mature. Bloom applications can start when the flower caps begin to drop and the flower parts are exposed. This year is turning out to be drier in many parts of the state, which is helpful for disease prevention as rain splash facilitates spore dispersal and infection.
Similar to the note on apples in the above section, this is a time for growers to be extra careful of pre-harvest intervals (PHI) for products being applied, especially for early-harvested varieties. Additionally, remember to pay attention to FRAC numbers to prevent fungicide resistance.
Nitrogen application recommendations around bloom
Recommendations for nitrogen applications for grapes in the Midwest used to be much earlier, but more research has shown that grapes tend to use nitrogen from their own reserves from bud break until bloom. Earlier nitrogen applications can thus be more susceptible to loss during periods of heavy or frequent rainfall. This means that near-bloom applications can be helpful for chemical nitrogen applications, while split applications are still recommended, and growers should avoid fall applications.
Article and video: Petiole sampling for grapes
Bloom is the first period during the season when grapes can be sampled for petiole nutrition analysis. The second time period is during veraison, so if you miss it during this period, you can still prepare to take samples later this summer. Nutrient levels within the grapevine vary throughout the summer, so it’s important to take samples at the correct time.
To learn more about taking petiole samples, check out the following resources…
Video: Petiole Sampling (UMN Video by Annie Klodd)
Article: Test, don’t guess: Is foliar nutritional analysis right for your fruit crops this growing season?
Sucker and water sprout management
Image: two suckers are growing from the base of this vine. Since this vine already has two healthy trunks establishing on their second year, neither shoot is necessary to keep; however, it is ok to keep one shoot trained upright this season, which can either be used if winter damage happens in a future year, or removed if unnecessary during the next growing season.
Grapes regularly produce suckers, originating from the base of the grapevine, and water sprouts that come off the trunk of the vine. Production methods traditionally have advised to remove all suckers and water sprouts from below the cordon, but sometimes it can be helpful to keep two water sprouts on either a single trunk, or one on each trunk for double-trunk training.
This step is critical to the process of cane pruned vines that require renewal canes each year. If these water sprouts are meant for renewal, it can be helpful to remove fruit to allow for more energy to go toward shoot growth.
Keeping a single sucker each year is another form of insurance in case trunk renewal is needed, but not practical for every grower to do. Additionally, remembering to remove the retained sucker the following year if no renewal is needed will also be important to prevent situations with three or more trunks being trained on a vine.
Blueberries
Growth stage update: Early green fruit set
Image: The blueberry variety Nelson—a highbush blueberry—is in the growth stage called early green fruit set at Little Hill Berry Farm, located in Northfield, Minnesota. Photo taken 06/02/2026.
Blueberries that are in the growth stage early green fruit set still have about a month to go before they are ready to harvest. For growers who are learning about blueberry production, Michigan State University Extension has an excellent resource that shows blueberry growth phases (see below).
Resource: Blueberry Growth Stages (MSU Extension)
Honeyberries/haskap
Growth stage update: Nearing harvest
Images: Boreal Beast is a honeyberry variety that ripens in June in Minnesota. Photos taken at Little Hill Berry Farm in Northfield, MN, on 06/02/2026.
Honeyberry harvest season is getting closer as some varieties, like Boreal Beast, begin to change color and sweeten. George Terwey of Haskap Minnesota mentioned this week that the berries typically need about two weeks from when they first change color and when they fully ripe. He also noted that his honeyberries seem like they are 5-7 days earlier than usual and are ripening less evenly.
If you didn’t catch the UMN interview with Haskap Minnesota (9 minute video) and want to watch it, you can access the video with the link below…
Video: Honeyberry/haskap farming 101
Day-neutral strawberries
Growth stage update: Fruit set
Image: A day neutral strawberry plant is grown under a high tunnel with landscape fabric and drip irrigation at Little Hill Berry Farm.
Day-neutral strawberries produce continuously from the time of the first harvest (timing dependent on planting time and weather conditions throughout the season) until they experience critical frost temperatures in the fall, in which high tunnels can help further extend their season.
The strawberries in this picture are grown under a high tunnel and were planted in mid-April. Some growers will practice removing the first flowers to allow plants to put more energy into establishing before harvest, but some skip this step as it requires extra cost for labor. Day-neutral strawberries are recommended to be grown as annuals, similar to vegetable crops, where they are planted each year. Some growers have tried overwintering them with varying results, but generally the yields are not consistent the following year.
For more information on day neutral strawberries, check out some of our previous articles posted on the UMN Fruit and Veg News site earlier this year, along with the UMN Extension website:
Organic Day-neutral Strawberry Insecticide Efficacy for Tarnished Plant Bug
Spotted-wing drosophila parasitoid detected in Minnesota: what growers should know
Biodegradable Paper Mulch: An Organic Option for Day‑Neutral Strawberry Growers
Does mulch help manage pests in organic day-neutral strawberries?
Webpages: UMN Extension day-neutral strawberry farming
Thank you to our farm and ag professional partners for contributions to the UMN Fruit Update series. Non-credited photos in this article were either taken by Madeline Wimmer or within the UMN Extension system.
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