Blueberries (Vaccinium) make excellent ornamental edibles. Evergreen or deciduous shrubs, they are worthy of inclusion in the garden where they offer multiple seasons of interest. Easy to grow and rewarding, they produce charming bell-shaped flowers in spring, their beautiful foliage turns fantastic shades of gold, red or purple in fall. Not to forget their delicious and juicy berries which are very rich in antioxidants and other nutrients and can be enjoyed in desserts, smoothies, or fresh on the bush. Vaccinium are easy to grow and not prone to insect or disease issues. They can be successfully grown in any size garden or planted in containers provided they are grown in acidic soil.
Types of Blueberries
- Vaccinium corymbosum (Highbush Blueberry)
Native to eastern North America - shrub and major blueberry producing species in commerce. Over 50 cultivars have been developed. Northern highbush varieties grow in hardiness zones 4-7. Southern varieties grow in hardiness zones 7-10. Highbush blueberries typically grow up to 6-8 feet high (180-240 cm) and yield up to 7 pounds per plant. They meld right into a shrub border or can be used as a hedge by itself.
- Vaccinium angustifolium (Lowbush Blueberry)
Native to northeastern North America - Lowbush blueberry is a low-growing shrub that ranges from only 6-24 in. tall (15-60 cm) and spreads by means of underground stems to form a dense mat. Hardy to zones 3-7, it yields about 5 to 10 pounds per 100 square feet. The blueberries are generally smaller, sweeter, and less aromatic than those of highbush blueberries, although the flavor varies from plant to plant. Lowbush blueberries are ideal as a ground cover. You may interplant them with small spring bulbs whose dying foliage will be hidden as the leaves of your Lowbush blueberry unfold.
- Half-High Blueberries are hybrids of highbush and lowbush types. They mix the benefits of highbush (large fruit) with the benefits of lowbush (cold tolerance) and grow to a height intermediate between the parents. They are useful for cold climates (hardiness zones 3-7) where a highbush equivalent is desired.
- Vaccinium ashei (Rabbiteye Blueberry)
Native to the Southeastern US - Rabbiteye blueberry is a suckering shrub that can grow up to 15 ft. tall (450 cm). More tolerant of hot weather and dry soils than its cousins, it is hardy to zones 7-9. It yields about 15 pounds per plant. The blueberries are small, often not as highly flavored, and have a thicker skin that lets them develop full flavor even under hot conditions. Rabbiteye blueberry can be added to the shrub border, used as a hedge or simply stand as a specimen shrub.
- Blueberries should be planted in early spring.
- Blueberries thrive in full sun or part shade, but however, you will harvest more fruits if you plant your blueberries in full sun.
- Blueberries are best grown in well-drained, moisture-retentive, organically rich, acidic soil (4.0 to 5.0). Sandy loam is preferred.
- Plant in a sheltered site and provide a good organic mulch (3 in. deep or 7 cm) to control weeds and protect the roots from heat.
- Do not allow the plant to produce fruit for the first year or two after planting. Pinch back any flowers developing on newly set plants to allow the energy to go to growth.
- Although blueberries are self-fertile, cross-pollination produces the best fruit crop (larger berries and larger yields). For optimal pollination and yield plant more than one variety with the same bloom time. Space your plants 4-5 ft. (120-150 cm) apart in rows that are 9-10 ft. apart (270-300 cm).
Blueberries need annual pruning winter,while the bushes are dormant, after the plants have been in the ground for about six years (a highbush blueberry stem typically remains productive for about six years).
- First 2 years: no pruning required. Simply remove any dead or damaged branches.
- Remaining years:
Highbush Blueberry: make large shaping cuts — Remove all low-spreading branches and the oldest canes if they are weak, particularly if in the center of the plant. Head back the upright bull shoot" to the desired height to keep the bush from growing too tall. On the remaining canes, systematically thin out the shorter, thinner shoots, leaving enough of the thick shoots to bear the crop and make new growth.
Rabbiteye Blueberry: same pruning as above but prune just enough to keep the center of the bush from becoming too shaded and to keep the plants from growing too tall, selectively cutting the oldest and largest stems to the ground.
Lowbush Blueberry: the best fruits are borne on the youngest stems, especially those growing directly from the underground stems. Prune these plants severely, cutting them completely to the ground every few years.
Pests and Diseases
Blueberries are not affected by serious pest or disease issues.
- Birds love blueberries as much as we do, so plants may need to be covered with netting as the fruit begins to ripen in order to protect the crop.
- Chlorosis (manganese and iron deficiencies) will cause decreased growth, yellowing foliage, early defoliation, and severely weakened plants.
- Potential but infrequent disease problems include stem blight, root rot, anthracnose, cane cankers, mildew and botrytis. Blueberry maggot, cherry fruit worm and spotted wing drosophila may attack the fruit. Mummy berry is a fungal disease that causes the berries to shrivel and drop.