High-bush Blueberries (Vaccinium corymbosum) are shrubs to about 2m tall. They have a low drought tolerance, however, and will normally require irrigation.
They have shallow roots and a preference for acid soils (ideally pH 4.5 5.0). They will grow well in cool temperate climates, with warm summers and where soils have high water holding capacities. Soils high in organic material are best (peat soils are ideal). Chilling hours that are required to overcome dormancy varies according to the cultivar but can range from 150 hours through to 1000 hours.
Culture
Spacing for plants should be about 1.5m x 3m and installation of trickle irrigation is preferred, as overhead sprinklers may cause fruit splitting as they approach maturity. Pruning is only required to maintain shape and vigour (ie. removal of weak canes and keeping the centre of the plant fairly open). Harvesting is generally by hand at least one week after the fruit attains its blue colour and every week through the season. This is the most costly aspect of production, although mechanical methods have been developed.
Problems
Apart from light brown apple moth and grey mould, the worst pests are birds and the plants will usually need to be caged. This may be the most expensive item in the establishment of a commercial plantation.
Although most varieties of blueberries do not require a cross pollinator, fruit yields are higher with cross pollination. Rabbit eye cultivars however often do require cross pollination. It is best to plant at least two different varieties that flower at the same time to achieve this.
There are many cultivars available suited to a broad climatic range following are just a few of the more popularly grown cultivars.
High Bush varieties
‘Bluecrop’ - well flavoured mid season, high yielding cultivar produces large fruit but requires excellent drainage.
‘Brigitta’ - large upright bushes to 2.4m produce large flavoursome fruit late in the season. Great for freezing, as well as fresh eating and has excellent keeping quality. Plant another variety for cross pollination. Care is needed during harvest as fruit drops readily. Flowers 2 weeks after ‘Blue Crop’.
‘Elliott’ - a late season cultivar of an upright and semi-vigorous habit – it has extremely high yields and firm light blue slightly tart berries. Suited to cooler areas.
‘Chandler’ - high yielding and well flavoured, late summer to early autumn producer bush usually less then 2m. Self-pollinating.
‘Earliblue’ - 2m upright bush that produces very early (mid summer) flavoursome, light blue, sweet fruit. flowers the same time as ‘Chandler’ - excellent for cooler climates.
‘Reka’ - upright, vigorous, high yielding cultivar with mid sized flavoursome, firm fruit it ripens between ‘Earliblue’ and ‘Bluecrop’. New Zealand variety suited to high chill areas and tolerant of varying soil conditions.