Blueberry Bush Guide — Growing Out The Box

Blueberry Varieties

While Northern and Southern blueberry bushes are considered self-fertile, meaning they can produce fruit without a plant pollinator, planting two of the same varieties of blueberry bushes together is not the best approach for maximizing fruit production. Here's why: Limited genetic diversity: Even though Sweetheart is self-fertile, cross-pollination (pollination between two different varieties) generally leads to better fruit set, larger berries, and more consistent yields. Planting two of the same variety doesn't provide this benefit of genetic diversity.

Will a Rabbiteye cross pollinate with a half high?

Different species

Rabbiteye blueberries (Vaccinium virgatum) and half-high blueberries are different species. Rabbiteye is a distinct species native to the southeastern United States, while half-high blueberries are hybrids between highbush (Vaccinium corymbosum) and lowbush (Vaccinium angustifolium) blueberries. Cross-pollination between different species is generally less effective than within-species pollination.

Chromosome differences

Rabbiteye blueberries are tetraploid (4 sets of chromosomes), while half-high blueberries are also tetraploid but from different parent species. These chromosomal differences can hinder successful cross-pollination and reduce the viability of any resulting seeds.

Bloom time differences

Rabbiteye blueberries typically bloom later in the spring compared to half-high blueberries, which tend to bloom earlier. This difference in bloom times means that the flowers of the two types may not be open at the same time, making cross-pollination difficult or impossible.

What does this mean for fruit production?

If cross-pollination between a Rabbiteye and a half-high blueberry does occur, it may result in:

Reduced fruit set
Smaller berries
Inconsistent results

Recommendation

For optimal fruit production, it's best to plant blueberry varieties that are compatible with each other. This means choosing varieties within the same type — for example, planting two different Rabbiteye varieties together, or two different half-high varieties. This ensures better cross-pollination, leading to improved fruit set, larger berries, and more consistent yields. Sticking to cross-pollination within the same type (Rabbiteye with Rabbiteye) is the best approach.

Cross-Pollination Chart

View Cross-Pollination Charts →

Blueberry Bush Varieties

What is a Northern Highbush Blueberry Bush?

Northern Highbush blueberries (Vaccinium corymbosum) are the most widely cultivated blueberry species in the world. They thrive in cooler climates with cold winters and are known for producing large, flavorful berries. Most require 800–1,000 chill hours and grow best in USDA zones 4–7.

What is a Southern Highbush Blueberry Bush?

Southern Highbush blueberries are hybrids developed for warmer climates. They require fewer chill hours (150–500) and are ideal for USDA zones 7–10. They produce large, sweet berries and are well-suited for home gardens in the South.

What is a Rabbiteye Blueberry Bush?

Rabbiteye blueberries (Vaccinium virgatum) are native to the southeastern United States. They are heat-tolerant, drought-resistant, and thrive in USDA zones 7–9. They require two different varieties for cross-pollination and produce abundant crops of medium-sized berries.

What is a Half-High Blueberry Bush?

Half-High blueberries are compact hybrids between Northern Highbush and Lowbush varieties. They grow 2–4 feet tall, are extremely cold-hardy (USDA zones 3–6), and are perfect for small gardens, containers, and northern climates.

What is a Lowbush Blueberry?

Lowbush blueberries (Vaccinium angustifolium) are wild-type plants that grow low to the ground (under 2 feet). They are extremely cold-hardy (USDA zones 3–6), spread by rhizomes, and produce small, intensely flavored berries prized for baking and preserves.