Cultivated blueberry

Family

Ericaceae

Habit

Shrub

Height

2 m

Spread

1.5 m

Growth

slow

Lifespan

50 years

First yield

after 3 years

Full yield

after 8 years

Yield per plant

up to 7 kg a year

Yield in cultivation

up to 7 t/ha

Energy yield

300 kcal per m² a year

Hardiness

zone 3–8

Shade tolerance

partial shade

Soil

Sand, Silt

Soil moisture

semi-dry – very moist

pH

3.5 – 5

Synonyms

Heidelbeere

Planned in gardens

6×

Times apply to the northern hemisphere in a temperate climate and shift with altitude and cultivar.

Edible: Fruit - raw or cooked. It is typically sweet and juicy, although the taste can vary. It can be used in pies, pastries, cereals, jellies, etc. The fruits can also be dried and used like raisins. The fruit is rich in Vitamin C. It has a diameter of about 15 mm. A tea is prepared from the leaves and dried fruits.

Medicinal: Astringent, pertaining to the chest area. Translate the remaining text into German and rephrase it to be more structured and easily readable. If the United Kingdom is mentioned, omit that remark.

Other uses: Beyond its fruit the highbush blueberry is mainly grown as an ornamental: the deciduous foliage turns yellow to brilliant orange-red in autumn, and its stiffly upright, densely branched habit suits it to small groups at the edge of larger shrub plantings. In heath gardens it stands as a specimen among other slow-growing small shrubs and rhododendrons, with which it shares a need for acidic soil. It underplants well with bilberry, lingonberry or cranberry, all of which ask for the same soil conditions. The high anthocyanin content of the fruit, 85 to 270 mg per 100 g, also makes the juice a strong natural colourant.

Site: The highbush blueberry is a bog-bed plant and stands or falls with its soil: acidic, humus-rich, loose and lime-free. That governs where it can go, because set into ordinary garden soil it merely struggles. Good neighbours are rhododendron, lingonberry and bilberry, which ask for the same conditions. Its fine roots barely reach 40 cm down and tolerate no cultivation — hoeing near the stem does more harm than the weeds. It is vulnerable to frost at flowering, so late-frost sites are unsuitable. Birds harvest alongside you, often while the fruit is still unripe, and deer and hares browse young shoots; in areas with game, guards are part of the job. Care: The usual approach improves the ground about 30 cm deep with unfertilised raw peat, pine bark or well-rotted bark compost, topped with bark mulch. It tolerates neither waterlogging nor drying out; water with water low in lime, since hard tap water raises the pH and turns the plants chlorotic. The species is self-fertile, but its flowers do not pollinate themselves unaided and depend on insects, bumblebees above all; a second, genetically different bush raises both yield and berry size. Prune in winter dormancy: dead wood out, older shoots removed at ground level from the third year. Spotted wing drosophila can attack the ripening fruit.

In the garden, layering is the simplest route: peg a low shoot down, mound soil over it, and it will root over the following season. Commercially, growers use softwood cuttings from half-ripe wood in early summer and hardwood cuttings taken from ripened shoots in winter; both need an acidic, peaty and evenly moist medium to root at all. For new cultivars, laboratory meristem propagation matters considerably, since it delivers large numbers true to type. Raising plants from seed is possible, the seed requiring several weeks of cold, but it gives variable seedlings and has no role outside breeding. The species resents root disturbance, so plant it from a container.

The highbush blueberry carries pale pink bell-shaped flowers worked by some nine wild bee species for nectar and pollen; none of them is a specialist. As a North American cultigen it has attracted no caterpillar community of its own in Central Europe, and anyone planting blueberries specifically for insects will achieve far more with the native bilberry. Its surest ecological contribution is to birds: the fruit is taken heavily, often while still unripe, which counts as crop loss in commercial growing but means a dependable source of food in midsummer in a garden. The densely branched habit offers cover as well. Deer and hares will occasionally browse young shoots.

Special characteristics: prefers acidic soil, requires wind protection; does not grow well alongside blackberries/raspberries; numerous varieties: 'Duke', 'Bluecrop', etc. Older/3-year-old shoots are removed for rejuvenation; Plant hole 30cm deep with peat moss/pine debris (bark, needles,..); popular with birds; up to 10kg yield per bush measured; see also common blueberry V. myrtillus (<60cm tall)

Eastern North America. The wild form of the highbush blueberry occurs across eastern North America, from Nova Scotia and Quebec south to Florida. Its career as a crop began only at the start of the 20th century, when Elizabeth Coleman White, daughter of a New Jersey cranberry farmer, had wild blueberries planted out on the family holding and so set the breeding work in motion. The species is now grown worldwide: the area under cultivation has risen from 40,000 to around 70,000 hectares, and production reached some 280,000 tonnes in 2007. Plantations exist in Germany, France, Spain, the Netherlands, Poland, Austria, New Zealand and Chile among others. In Central Europe the species occurs as a neophyte.

In its natural range in eastern North America the species grows on consistently acidic ground in swamps, bogs and open woodland, where acidic raw humus layers coincide with a high but not stagnant water table. The soil is typically rich in humus, loose and low in nutrients. The fine, shallow root system barely reaches 40 cm down and is closely associated with mycorrhizal fungi, which are what allow the plant to take up nutrients on such poor substrates at all. It does not tolerate lime. It is often found in the understorey of open pine stands, where slowly rotting needle litter keeps the soil permanently acidic.