Duke Blueberry
Northern Highbush · Zones 4–7 · Early — first of the season
Check price at Stark Bro's Plan its pollination partner
Released by the USDA program in Beltsville, Maryland in 1987 and still one of the most widely planted early varieties for home and commercial growers alike. Duke blooms late for an early variety — a quiet advantage, because late bloom dodges more spring frosts — then ripens its whole crop in a fairly tight window, which suits freezing and baking days.
Specifications
| Type | Northern Highbush |
| USDA zones | 4–7 |
| Chill hours | ~800–1,000 hours below 45°F (sources vary slightly by nursery stock — confirm with your seller) |
| Harvest season | Early — first of the season |
| Mature size | 4–6 ft tall |
| Berry | Large, firm |
| Flavor (nursery descriptions) | Sweet-tangy, mild and crisp — a fresh-eating favorite in nursery descriptions |
| Expected yield | Mature highbush commonly 8–15 lb per bush in good years (extension range for the type) |
| Container suitable | Better in the ground; very large pots only |
Pollination
This variety is self-fertile, so one bush will fruit on its own — but a compatible second variety planted nearby reliably means more and larger berries, which is why nurseries and extension guides recommend planting in pairs or trios.
Good partners for Duke:
- Patriot — Northern Highbush, Early, zones 3–7
- Bluecrop — Northern Highbush, Mid-season — the peak, zones 4–7
- Blueray — Northern Highbush, Early to mid, zones 4–7
Before you plant
- Soil pH 4.5–5.5, tested before planting — the pH guide
- Full sun (6–8+ hours) and soil that never sits soggy
- Space highbush 4–5 ft apart, rabbiteye 5–6 ft, dwarfs 2–3 ft — planner
- Remove flowers in year one so the bush builds roots, not a handful of berries
Not sure Duke fits your yard?
Run the Variety Finder with your zone and space — it only recommends varieties whose chill hours and size actually match.