In Maine, when one mentions blueberries tiny lowbush ones are the subject. These plants usually grow shorter than 12 inches. They occur naturally and are harvested by raking and winnowing the fruit.
Farmers employ weed, insect and disease control measures. They also mechanically prune or burn the fields, but they don’t tear up and replant. Lowbush are the hardiest blueberries.
All other blueberry types are much taller. Some require two different varieties for cross pollination. Common types are northern highbush, half highs, southern highbush and rabbiteye blueberries. All blueberries belong to the genus Vaccinium.
As one might expect half high types were crosses of lowbush and highbush types. They stand about four feet tall and are also very hardy. Snow usually protects most of the plant in a typical northern winter. This type isn’t adaptable to our hot summers.
Northern highbush types were collected from the wild and bred for fruit quality and fruiting season. While mainly considered northern blueberries, some common cultivars adapted to this area are: Blue Jay, Blue Ray, Patriot, Chandler and Darrow. Their advantage is that they don’t require cross-pollination. As one would expect from the name, a disadvantage is that our summers are sometimes a bit hot for optimal production. Plants might be stressed.
Southern highbush blueberries might be a better choice. They are generally self-fertile but almost always benefit from cross-pollination. Plant at least two different varieties. Another thing to consider is that the blueberry cultivars flower at the same time. Many don’t. O’Neal, Blue Ridge, New Hanover, Croatan and Bounty are cultivars adapted to coastal North Carolina.
Rabbiteye blueberries also will grow well here. They are nearly self-sterile, meaning cross-pollination is necessary. These are primarily grown in the Piedmont region as they are well adapted to upland clay soils.
Plants are generally taller than southern highbush varieties. Some plants might eventually reach 15 feet. This could pose a problem for people wanting more compact bushes. Popular varieties of rabbiteye blueberries are: Climax, Premier, Onslow, Powderblue, Tifblue and Columbus.
Rabbiteye types tolerate hot weather better than any other blueberry. Thay also are the least winter hardy. Usually this isn’t a problem for our area, but this past winter might have generated a little winter kill on some rabbiteye blueberries here.
All blueberries require soils with acid pH and high organic matter. Soil pH 4.5 to 5 is best. Plants require moist soils, but poorly drained ones should be raised, amended in some way or avoided. Blueberries are not heavy fertilizer users, so more is not better. Also, for best results, any nitrogen should be in the ammonium not the nitrate form
It’s difficult for some folks to remove fruit, but for best long-term results flowers and fruit should be removed in the establishment year. If plants become well established, they should begin to fruit heavily by their third year.
Plants should be pruned in the dormant season. Remove old and weak canes and generally shape the plants. Don’t be afraid to remove some fruit buds as fewer flowers generally means larger fruit. Another thing to consider is to always encourage pollinators.
Ted Manzer teaches agriculture at Northeastern High School (firstname.lastname@example.org).