NORTHBLUE blueberry

General information & origin

• ‘Northblue’ is a half-high variety (hybrid between highbush and lowbush), combining the vigor of highbush and the hardiness of lowbush.
• It was introduced in 1983 (University of Minnesota).

Main characteristics

• Hardiness zones    
  • Zones 3 to 7. Resistant to cold winters; can withstand temperatures as low as approximately -35°F (≈ -37°C) in good conditions.
    
• Size & habit    
  • Compact shrub (“half-high”), approximately 60-90 cm tall (≈ 2-3 ft) and 80-100 cm wide, depending on the source.
    
• Foliage & appearance    
  • Shiny leaves, green in summer, turning beautiful shades of orange-red to dark red in fall. Spring flowering with white (sometimes slightly pink) bell-shaped flowers.
    
• Fruit    
  • Medium to large, dark blue, firm berries with a good flavor—often described as “wild blueberry taste.” Cooked or fresh, they hold up reasonably well.
    
• Harvest time    
  • Mid-season (midsummer)—July to early August depending on climate.
    
• Yield    
  • Varies depending on conditions, but generally good: several sources mention ≈ 3-7 lb (≈1.4-3 kg) per bush in good conditions.

Strengths & advantages

• Highly hardy → Ideal for regions with harsh winters.
• Compact plant → Practical for small gardens, pots, vegetable gardens, borders.
• Good taste & firmness → For fresh consumption, cooking, freezing.
• Aesthetic appeal → Beautiful flowering, striking fall colors, attractive landscaping.

Constraints & things to watch out for

• Even though the variety is self-fertile (or “self-fruitful”), yields are better if another compatible variety (another half-high) is planted nearby. Cross-pollination helps fruit size and quantity.
• Requires well-drained, acidic soil (ideal pH ≈ 4.5-5.5) rich in organic matter. Soil that is too alkaline or compact causes problems (chlorosis, low yields).
• Requires sufficient light → full sun or light partial shade for good yields and beautiful fruit color.
• Limited productivity in the first few years, as with many blueberry bushes: the shrub must establish itself.

Recommended growing measures

Here are some tips to maximize your success with ‘Northblue’:

1. Location: Choose a spot with full sun or at least 6 hours of direct sunlight per day.
2. Soil: Add well-decomposed compost and organic mulch (bark, leaves, etc.) to maintain moisture and acidity. Test the soil to ensure the pH is between ~4.5-5.5.
3. Spacing: Space plants ~90-100 cm apart so that each shrub has room to grow. If smaller, space them closer together.
4. Maintenance: Prune old wood (3-4 years and older) to encourage new growth. Remove dead/diseased wood.
5. Winter protection: Although hardy, good mulching around the base helps, especially if the soil is sandy or exposed to wind.
6. Pollination: It is a good idea to plant another compatible half-high or highbush variety if possible (e.g., ‘Northcountry’, ‘Polaris’) to improve yield and fruit size.