A member of the Heath family which includes Azaleas, the genus Vaccinium (Blueberry)
comprises 37 species plus hybrids. A few of these are used in commercial fruit production.
Two types of blueberry are appropriate for fruit production in warm climates: Southern Highbush
Blueberry, a collective name for Highbush Blueberry (Vaccinium corymbosum) hybrids with various
southern blueberry species; and Rabbiteye Blueberry (Vaccinium ashei).
Southern Highbush blueberries are larger, have thinner skin, are juicier, and ripen about a
month sooner than Rabbiteye.
Rabbiteye blueberries are sweeter but have thicker skin which gets tougher after freezing.
Rabbiteye shrubs are more drought tolerant, more tolerant of higher pH ranges (5.5-6.5),
and less prone to disease than Southern Highbush shrubs. But Rabbiteye grows to be a monster 20'
high shrub unless hedge trimmed or grown in a container.
"Wild" blueberries are from the Lowbush Blueberry (Vaccinium angustifolium), which grows in
northeastern North America from Canada to Virginia.
Lifespan: 20-50 years.
Leaf retention: Semi-evergreen or deciduous, based on the length
of time before dropped leaves are regrown.
Growth rate: Moderate.
Mature Size: 4-6' high and as wide is typical for a container plant.
Flowers: White to pink, small, waxy, hanging lantern shaped,
Bloom: Late winter or spring.
Self-fruitful: Usually. A different cultivar is needed for
cross pollination to produce a higher yield even when a plant is self-fruitful.
Years before fruiting: None, but all flower buds should be removed
the first year so that the plant can spend its energy developing roots instead of fruit.
Fruit: Spherical shape, dark blue skin, edible. Tiny seeds.
Months for fruit to ripen: 2.
Storage after harvest: Place in a sealed glass or plastic container
without washing and refrigerate for up to 2 weeks. Washing causes blueberries to last no more than 5 days
in a refrigerator even when dried on a paper towel. Frozen blueberries will last up to one year.
Leaves: Green, smooth edges, oval with pointed tip to broadly
Stems: No thorns. New canes (main branches) grow from the root crown.
Roots: Shallow, mostly within the top 7" of soil, weak.
Cultivars of Note:
for regions with hot summers
'Jewel' 200 chill hours, high yield commercial variety,
'Misty' 150 chill hours, especially adapted to heat, self-fruitful
'Sharpblue' 200 chill hours, long bearing season, self-fruitful
'Southmoon' 200-300 chill hours, taste test winner, self-fruitful
'Sunshine Blue' 150 chill hours, semi-dwarf, self-fruitful
Wildlife: Attracts bees and birds. Plants must often be netted to
avoid bird predation.
Toxic / Danger: No.
Origin: North America. Most commercially grown food crop species
originated on the east coast.
Cultivation and Uses
USDA hardiness zones: 7-10 for most low chill cultivars.
Chill hours: Select cultivars needing 300 chill hours or less
in USDA zones 9-10.
Heat tolerant: Yes.
Sun: Full sun in the morning, afternoon shade in USDA zones 9-10.
Drought tolerant: No.
Water after becoming established: Daily. Never let the soil dry
out entirely. A drip emitter system is ideal for watering blueberries. Make sure all containers drain well.
Blueberries are "calcifuges", very sensitive to calcium and sodium salts in the water, salts typically
found in desert water sources. Collected rainwater is best.
Soil: Well drained, high in organic content, pH 4.0-5.5 (very
strongly acidic). Blueberries must be grown in large containers to maintain soil acidity in regions with
alkaline soils. If plants show a nutrient deficiency, it is usually because the pH is too high.
For residential gardening, the soil should be composed of 50% aged compost and 50% sand. Premium potting
soil without nitrates or ground pine bark (not wood) are often used in place of aged compost.
Fertilize: Use fertilizers without nitrates formulated for
acid-loving plants. Nitrates will kill the plant. Azalea and rhododendron fertilizers work well.
Mulch: Spread organic material 3" high around the plant but keep
it one foot away from the root crown. This will reduce heat stress and water loss.
Planting: Use a 20-24" diameter container. Locate the containers
where they will get appropriate sun exposure and good air circulation.
First Year Care: Do not fertilize during or after planting until
new growth has started. Remove all flower buds the first year so that the plant can spend its energy
developing roots instead of fruit.
Prune: In early winter, remove all dead wood and low-growing
branches which are more prone to disease. Berries grow on one year and older wood. Cut off short shoots
that have fewer leaf and flower buds to open the plant out. If done properly, 50-75% of flower buds
will be removed so that the plant will have fewer fruit and can grow them to a larger size.
The oldest canes (vertical branches growing from the root crown) are the largest in diameter and produce
less fruit after six years. After six years, start removing the oldest (largest diameter) canes but not
more than one-sixth of all canes. Cut them at ground level just above the root crown. On average, you
will be removing only one or two canes, all six years old.
Litter: Moderate. Keep the area around the plant free of fallen
leaves, branches and fruit to prevent fungal diseases.
Uses: Edible fruit, ornamental, bird garden.
When growing blueberries, buying two different cultivars is recommended because cross-pollination
greatly increases fruit set. Growing blueberries in containers to ensure properly acidic soil is a must.
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