BLUE FOCUS NEWSLETTER- May 2026

 

Hello everyone,

The wild blueberry bloom and pollination season has arrived across the province, bringing one of the most vibrant and exciting times of the year in our crop fields as pollinators return in full activity. The month began with cool, wet conditions, shifted quickly into a period of hot and dry weather in mid-May, and is now ending with a prolonged stretch of rain and soggy field conditions.

At this point, moisture is welcome in many areas of the province; however, over the next two to three weeks, maintaining a balance between adequate soil moisture and favourable flying conditions for bees will become increasingly important for successful pollination. Frequent temperature swings and rapidly changing weather patterns have also accelerated crop development in some regions, with noticeable changes in blueberry growth stages occurring within only a few days.

The combination of rapid crop development and highly variable weather has created challenges for field operations and management scheduling this spring. Careful monitoring of bloom progression, pollinator activity, and field conditions will remain essential during this critical production window.

Wishing everyone a productive and successful pollination season. Take a moment to enjoy the colours, activity, and sounds of the bloom season in your fields.

 

Hugh Lyu

Wild Blueberry Specialist, Perennia

hlyu@perennia.ca; 902-890-0472.

May 29, 2026

Table of Contents: 

May Wild Blueberry Production Highlights

Weather Updates

Upcoming Events

 

 

May Wild Blueberry Production Highlights

 

After a slow start to crop development in April, improved moisture and warmer temperatures accelerated wild blueberry growth throughout May. Over the last two months, much of the attention across the province has focused on assessing the impacts of last year’s drought on the 2026 crop, managing Monilinia Blight, and completing herbicide applications in sprout fields.

Crop stage development continues to serve as the foundation for field management planning. While the 2026 season initially appeared delayed, current observations suggest crop development is running approximately 1 to 1.5 weeks behind the 2025 season. For many growers, this timing is more consistent with traditional production schedules. However, one notable trend this spring has been the relatively uniform crop development across production regions. Unlike in previous years, when crop stages often varied significantly across regions, many areas are now reaching critical management stages in a much shorter timeframe, increasing pressure on scheduling field operations.

 

Drought Impacts on the 2026 Crop

Assessment of drought impacts on the 2026 crop began in late March through stem sampling in major wild blueberry production regions. Evaluations focused on stem height, fruit bud number and size, crop health, and overall yield potential.

Key observations include:

• Drought conditions during the 2025 sprout year, particularly from July through September, significantly affected wild blueberry growth and fruit bud development. This period is critical for fruit bud initiation and development.
• Drought severity varied considerably depending on precipitation levels, soil moisture availability, and soil properties. Areas with sandy soils and low organic matter experienced the greatest impacts, including reduced stem growth, fewer fruit buds, and smaller bud sizes, indicating lower nutrient reserves available for spring development.
• Uneven crop development is now being observed both within fields and among regions. Fields that received more rainfall and retained soil moisture more effectively generally show average to normal crop development. However, even in otherwise healthy fields, isolated drought-stressed patches remain visible and continue to resemble conditions seen in more severely affected areas.
• The drought created substantial regional variability in crop potential across the province, making overall yield predictions more difficult at this stage of the season.
• While many areas currently show average crop appearance and bloom progression, some severely impacted fields continue to face management challenges and concerns regarding input decisions for the remainder of the season.

 

Crop Field and Management Updates

• Spring bud break progressed slowly early in the season. However, several consecutive days of warm temperatures combined with adequate rainfall in early May rapidly accelerated crop development. In some areas, fields advanced from F1 to early F2 stages (30–40% F2) within only two days.
• Dry and warm weather conditions during the Monilinia Blight infection period resulted in a relatively short infection window of approximately one week in most Mainland areas. Based on weather conditions and field observations, a single fungicide application appeared sufficient in many areas this season.
• Following the warm mid-May period, several frost events occurred between May 22 and 24. Minor frost injury was reported in some early flowering fields, particularly in the Oxford, Debert/Belmont, and parts of the Pictou regions. Overall damage levels appeared limited, although affected fields may still experience localized bloom injury and some yield reduction.

Sprout Field and Management Updates

• Sprout field emergence followed a similar pattern to crop fields, with rapid plant emergence occurring after the early May rainfall and warmer temperatures. This created additional scheduling challenges as herbicide applications overlapped with blight management activities in crop fields.
• Most growers were able to complete pre-emergence herbicide applications before widespread plant emergence occurred.
• Current sprout field emergence appears normal across most production regions, helping reduce earlier concerns regarding potential drought impacts on sprout development. At present, most areas are reporting greater than 50% plant emergence.

 

Weather Updates

 

In this section, we provide regular weather updates to help growers track seasonal progress and support field management decisions. Key parameters reviewed include growing degree day (GDD) accumulation, seasonal precipitation trends, and current drought conditions across Nova Scotia.

 

1.    Wild Blueberry Weather Station GDD Summary (April 1- May 28)

 

Figure 1 summarizes the growing degree days accumulated between April 1 and May 28 from selected wild blueberry weather stations across the province. Over the last two months, most mainland production regions have accumulated close to or more than 400 GDDs. This accumulation level is an important seasonal benchmark in both crop and sprout fields, as it is typically associated with mid- to full-bloom stages in crop fields and more than 50% plant emergence in sprout fields for next year’s crop.

As we move into June and the warmer summer months, daily GDD accumulation rates are expected to increase significantly, often reaching 20-25 GDDs or more per day. As a result, growers should expect rapid progression through crop stages and accelerated plant development over the coming weeks.

Figure 1. Wild Blueberry Weather Station GDD Summary (April 1- May 28)

 

 

2. Seasonal Perception Trends

 

Precipitation patterns and soil moisture levels remain a major focus during the 2026 production season in Nova Scotia. Since the beginning of the year, much of the province has experienced persistent dry conditions, ranging from Abnormally Dry to Moderate and Severe Drought classifications.

Although March precipitation was above normal in several areas and provided some temporary relief, many regions still received below-average precipitation overall in April (Figure 2). Data from the Kentville Research Weather Station compares current-year precipitation levels to long-term regional averages. As illustrated in the graph, April precipitation remained below average, indicating limited improvement in soil moisture recovery heading into the growing season.

May weather conditions have been more variable, with alternating rainy and dry periods throughout the month. Overall, conditions have become noticeably wetter, particularly during the final week of May. Additional precipitation during this period has been beneficial for improving soil moisture conditions and reducing dryness concerns across many production regions. A more complete seasonal assessment will be available once final May precipitation data are compiled.

 

 

Figure 2. 2026 Precipitation vs. Regional Historical Averages from the Kentville Research Weather Station.

 

 

3. Current Drought Conditions

 

The latest Canadian Drought Monitor update (April 30, 2026) reported that many regions across Canada received normal to well-above-normal precipitation during April. However, in Nova Scotia, below-normal precipitation in parts of the province contributed to the continued expansion of drought in several areas.

Despite March and April precipitation events, significant drought improvement was limited across much of the province. The encouraging development is that early May rainfall, combined with the widespread precipitation in the final week of May, has improved soil moisture and reduced some drought-stress concerns.

 

According to the April 2026 Canadian Drought Assessment Report:

“Across Nova Scotia, drought changes were mixed, with central areas seeing improvement and the reduction of Abnormally Dry (D0) conditions. Southern and northern regions experienced an expansion of Moderate Drought (D1), consistent with below normal precipitation.”

Figure 3. Canadian Drought Monitor, Conditions as of April 30, 2026.

 

 

Upcoming Events

 

1.      Wild Blueberry Virtual Grower Meetings- June and July

 

o   June 3 and June 17 Event page and registration link: https://www.perennia.ca/eventer/wild-blueberries-virtual-grower-meetings-2026/edate/2026-04-08/.

 

§  June 3, 2026. 8:30 AM- 9:30 AM

 

§  June 17, 2026. 8:30 AM- 9:30 AM

 

 

o   Wednesday, July 8, 8:30 AM- 9:30 AM. This event and its registration will be available soon. Please save this time. We will feature 2 guest speakers on two important topics:

 

§  SWD Talk by Matthew Peill, Integrated Pest Management Specialist, Perennia

§  Sprout Year Nutrient Input by Jessica D'Entremont, NutriAg

 

 

2.      WBPANS Field Day- June 24, 2026, Upper Onslow, NS

This year’s wild blueberry field day will be at the River Breeze Farm, 699 Onslow Road, Upper Onslow, NS.

2026 Production Updates and Seasonal Outlook for NS_ 7th light Line Post_ May 27

 

Hi everyone,

This week’s rain is timely and extremely welcome. The moisture helps improve soil conditions and reduce dust in blueberry fields after last week’s hot, windy conditions. Good soil moisture is essential for strong nectar production in wild blueberry flowers, which helps attract bees for pollination.

As we enter early summer, most attention is focused on blueberry flowers, particularly pollination, blight disease management, and frost concerns. The recent frost mornings (May 22–24) caused some damage to open flowers; however, the overall damage level remained low, and frost concerns were mainly limited to three areas: Oxford, Debert/Belmont, and Sunnybrae (Pictou). Below are updates and outlooks for the next 1–2 weeks.

Crop Fields

·         Damage to blueberry flowers. We will begin seeing more visible symptoms of frost and disease damage on flowers. I have already observed Monilinia Blight (Mummy Berry) infections on leaves in this year’s crop fields, and some growers have also reported frost damage to flowers. It is still early to observe significant Botrytis Blight symptoms, as infection activity is only beginning this week with the recent wet weather.

Figure 1 is an excellent resource from the University of Maine Wild Blueberry Research and Extension Group, illustrating blueberry flower damage and providing clear images and key points for distinguishing frost injury from disease symptoms.

Figure 1. Photo and information credits: University of Maine Wild Blueberry Research and Extension Group.

 

·         Bloom-period disease management. During bloom, two high-priority blueberry diseases — Botrytis Blossom Blight and Septoria Leaf Spot — become active and can cause significant yield losses. Fungicide applications remain an effective management tool during June; however, application frequency, product selection, and timing must be carefully planned to balance disease control and pollinator protection.

We strongly recommend that producers begin planning their bloom-period fungicide applications now, as favourable conditions for disease infection and susceptible bloom stages are currently occurring across Nova Scotia.

 

Sprout Fields

·         Post-emergence herbicide application. The timing for Callisto and Venture L applications is approaching in sprout fields. Following this week’s rainfall and improved soil moisture conditions, field conditions are becoming more favourable for application.

If goldenrod is your primary target species and you are using the growing degree day (GDD) guideline to time your Callisto application, we continue to recommend targeting approximately 400 GDD or when goldenrod reaches about 20 cm in height, based on current research and successful field experiences (Table 1).

·         Granular fertilizer application. Many sprout fields are approaching or exceeding 50% plant emergence, which is generally considered a good timing window for supplying nutrients to support active vegetative growth through the remainder of the growing season. Improved soil moisture conditions will also help nutrient availability and fertilizer uptake.

 

Table 1. Wild Blueberry Weather Station GDDs Updates

 

 

 

 

2026 Production Updates and Seasonal Outlook for NS_ 6th light Line Post_ May 23

Hi everyone,

With another week of rapid crop development, we are excited to see the bloom season beginning in blueberry fields across Nova Scotia. Bloom stages currently range from early bloom to approximately 10–15% bloom in most Mainland crop fields, indicating the need to introduce bees to support pollination. We expect the majority of fields to reach mid to full bloom by the end of next week.

There is no longer a Monilinia Blight infection risk once fields enter the bloom stage. Infection symptoms should become visible within the next week, and we will continue providing updates on blight levels this season. So far, this appears to be a light and fast-ending blight season due to the recent dry and windy conditions.

As we move further into bloom, we will also begin discussing other important diseases, including Botrytis Bloom Blight (Grey Mould) and one of the earliest leaf diseases, Septoria Leaf Spot.

In this post, we are focusing on frost risks during bloom, as Nova Scotia experienced two frost mornings this week. Fortunately, based on the bloom stage and temperatures recorded across blueberry regions, frost injury was not considered a concern. Please refer to the next section for more information on blueberry frost risks.

Sprout fields are also entering a rapid growth period as leaves continue to expand and new leaf buds emerge. Growers are encouraged to plan post-emergence herbicide applications (Callisto, Venture, Clethodim products) and fertilizer timings over the next two weeks.

Enjoy blueberry bloom season — and the sound of the bees buzzing when visiting blueberry fields!

Hugh

 

 

 

 

 

Blueberry Frost Risks

 

As blueberry fields enter early flowering, spring frost can pose a significant risk to blooms if low temperatures occur for an extended period while a high percentage of flowers are open. Figure 1 shows the minimum tolerated temperatures for different stages of blueberry buds and flowers.

 

When blueberry plants reach the fully open-flower stage, temperatures of -2.2 °C or lower can cause permanent damage to floral structures and reduce yield potential, especially if the cold conditions persist for more than 3–4 hours.

 

Figure 1. Blueberry Frost Risks

Fortunately, most fields are not yet at full bloom, and bloom percentages remain relatively low. The minimum temperatures recorded during the two frost mornings (May 22 – Figure 2; and May 23 – Figure 3) did not pose a significant frost risk to the current crop stages and bloom development in most fields. However, some localized areas and earlier-developing fields or patches may have experienced frost damage, particularly in Oxford and Debert/Belmont.

 

Next week will be a critical period as bloom percentages continue to increase, raising concerns about potential frost risks.

 

Figure 2- May 22 Lowest Temperatures across the Region

 

 

Figure 3- May 23 Lowest Temperatures across the Region

 

 

 

Wild Blueberry Weather Station GDDs Updates

 

 

 

2026 Production Updates and Seasonal Outlook for NS_ 5th light Line Post_ May 19

Hi everyone,

I hope you were able to take advantage of the recent stretch of suitable spraying weather to complete urgent applications, including pre-emergence herbicides in sprout fields and blight protection sprays in crop fields. Warm temperatures over the long weekend have accelerated wild blueberry plant development, and we are now transitioning into a new crop-management period. Both sprout and crop fields are showing rapid progression in growth stages.

In sprout fields, management attention will increasingly shift once plant emergence exceeds higher emergence percentages. Following this past Sunday, the application of “hot” pre-emergence herbicides is no longer considered safe due to increased risk of crop injury. Growers are encouraged to carefully scout fields and evaluate emergence levels before deciding whether additional herbicide applications are appropriate. For post-emergence herbicides such as Callisto and Venture L, applications remain slightly premature. Current forecasts suggest mid-summer–like conditions this week, with hot and dry weather expected, which may further influence herbicide timing decisions.

Most discussions this week are centred on crop fields. Many of you have been actively scouting and observing varying pictures of crop potential across fields. At this stage, estimating yield remains challenging. However, rapid bud development has advanced many fields to the F3–F5 stages (Figure 1). With continued warm weather over the next few days and drier conditions ahead, the risk of additional Monilinia blight (mummy berry) primary infection appears low. Once plants progress beyond the pink and white prebloom stage (F5), primary infection from ascospores is no longer a concern. Based on current conditions, it appears that one Monilinia blight spray may be sufficient for many crop fields this season.

The next major milestone to watch is bloom development, which will provide a clearer indication of crop potential and yield outlook.

We will continue monitoring crop development across the province and greatly appreciate growers sharing field observations. These reports help improve our understanding of plant responses following the 2025 drought and support better management recommendations moving forward.

Lastly, a reminder that the next virtual wild blueberry grower meeting will take place tomorrow morning (May 20, 8:30–9:30 AM). This special session will feature two guest speakers discussing:

·         Future blueberry field improvement practices (mulching)

·         Nutrient management strategies for wild blueberry production

To register, please visit:
Wild Blueberries Virtual Grower Meetings 2026 Registration

If you need assistance, please get in touch with Hugh Lyu at 902-890-0472 or hlyu@perennia.ca.

At the end of this blog post, you will also find a survey supporting Dalhousie Agricultural Campus research students studying farm equipment sanitation practices in Atlantic Canada. Your participation is greatly appreciated.

Have a great week — and welcome to summer!

Hugh

Figure 1. Wild Blueberry Crop Year Leaf and Fruit Bud Stages

 

Wild Blueberry Weather Station GDDs and Crop F2 Stage Updates

 

Table 1. Percentage of Wild Blueberry Floral Bud F2 stage

 light green (0-20% F2), dark green (20-30% F2), yellow (30-40% F2) and red (40-100% F2)

Wild blueberry production regions, NS	The average percentage of floral buds at F2
Cape Breton	>40% F2, Blight Spray is Needed in Crop Fields
Cumberland County	>40% F2, Blight Spray is Needed in Crop Fields
Colchester County	>40% F2, Blight Spray is Needed in Crop Fields
South West Nova Scotia	>40% F2, Blight Spray is Needed in Crop Fields
Hants County	>40% F2, Blight Spray is Needed in Crop Fields
Halifax County/ Musquodoboit Valley	>40% F2, Blight Spray is Needed in Crop Fields
Guysborough County	>40% F2, Blight Spray is Needed in Crop Fields
Pictou County	>40% F2, Blight Spray is Needed in Crop Fields
Antigonish County	>40% F2, Blight Spray is Needed in Crop Fields

 

 

2026 Production Updates and Seasonal Outlook for NS_ 4th light Line Post_ May 14

Hi everyone,

We are seeing rapid crop development in both sprout and crop blueberry fields following the recent warm temperatures and abundant moisture across the province. Traditionally, crop development varies by several days to weeks among regions and microclimates; however, this spring we are observing more uniform plant development across Mainland Nova Scotia.

 

Crop Fields — Blight Risk Increasing

Most Mainland crop fields are expected to surpass 40% F2, meaning blight protection is now required as soon as field conditions permit spraying.

Cape Breton crop fields are also progressing quickly and are expected to reach the 40% F2 threshold by this weekend, requiring blight applications early next week.

This timing will likely create spray scheduling challenges, as growers may encounter:

·         high winds,

·         intermittent rainfall,

·         and narrow optimal fungicide application windows.

Please continue monitoring weather forecasts closely and take advantage of available spray opportunities. Fruit buds are currently at highly susceptible developmental stages, and leaf buds also contribute to disease risk.

Once leaf buds unfold and reach the V2 stage (approximately 2–5 mm; Figure 1), they can host blight spores and support secondary infection cycles, which may later impact open flowers. This year, leaf bud development appears faster than fruit bud development in some fields, and drought-affected patches may show leaf growth without viable fruit buds.

 

Sprout Fields — Emergence and Herbicide Timing

Sprout field emergence has begun in many regions, particularly where growing degree days (GDD) have reached approximately 200 (Figures 2 and 3).

If you are planning herbicide applications:

·         Chikara and Ignite — Fields should be scouted carefully before application. After this week, applications may no longer be safe due to crop emergence.

·         Velpar, Sinbar, and Spartan — Applications remain acceptable but should be completed as soon as possible.

Many sprout fields experienced significant stress during last year’s drought. Emergence and early development remain a concern, and additional stress from late herbicide applications could further reduce stand recovery. Please consider alternative weed management strategies or products where risk is high.

 

Looking Ahead

Weather conditions after Friday and into the weekend and early next week appear more favourable for spraying operations. We encourage growers to prepare equipment and management plans to take advantage of these windows.

I hope everything goes smoothly during this busy period. We will provide another update following the long weekend.

Have a safe and productive week.

Hugh Lyu
May 14, 2026

 

Figure 1. Wild Blueberry Crop Year Leaf and Fruit Bud Stages

 

 

Figures 2 and 3. Wild Blueberry Sprout Plant Emergence

 

 

Wild Blueberry Weather Station GDDs and Crop F2 Stage Updates

 

 

 

We will continue providing updates on F2 stage percentages across different production regions as information becomes available throughout the season.

 

Table 1. Percentage of Wild Blueberry Floral Bud F2 stage

 light green (0-20% F2), dark green (20-30% F2), yellow (30-40% F2) and red (40-100% F2)

Wild blueberry production regions, NS	The average percentage of floral buds at F2
Cape Breton	30% F2
Cumberland County	>40% F2, Blight Spray is Needed in Crop Fields
Colchester County	>40% F2, Blight Spray is Needed in Crop Fields
South West Nova Scotia	>40% F2, Blight Spray is Needed in Crop Fields
Hants County	>40% F2, Blight Spray is Needed in Crop Fields
Halifax County/ Musquodoboit Valley	>40% F2, Blight Spray is Needed in Crop Fields
Guysborough County
College Grant	>40% F2
Pictou County
Sunny Bare	>40% F2
Blue Mt.	>40% F2
Moose River	>40% F2
Antigonish County
Monastery	>40% F2
New France	>40% F2