Most blackberry species (Rubus spp.) Are self-pollinating — they do not rely on outside sources. “Arapaho” (Rubus “Arapaho”) is a blackberry cultivar that does well in the temperate climates of U.S. Department of Agriculture plant hardiness zones 6 through 9. “Arapaho” is rather vigorous, but feeble pollination can decrease fruit production in several years. Improve the amount and quality of blackberries with a couple steps to boost pollination.
Pollination
Fruit does not form unless pollen is transferred in the stamen — the male portion of a flower — to the posture, or feminine part. Pollen is transferred by animals, insects, water and wind, and by hand. Some plants have perfect flowers where the blossom includes both the anthers which include the mud, and pistils, which develop into fruit. The plant can bear fruit from self-pollination or from pollen carried to it from another plant of the same kind. Most blackberry cultivars are self-pollinating, including “Arapaho.”
“Arapaho” Blackberry Bush
The “Arapaho” cultivar premiered in 1993. It’s a thornless, erect form of blackberry — the canes are self-supporting. “Arapaho” is hardy and also seems disease-resistant, using a Mammoth, sweet-tasting berry that ripens early in the summer. It’s known as a self-fruitful plant because it doesn’t require another plant to offer pollen. Honeybees act as pollinators, attracted to the pollen and nectar produced in blackberry flowers.
Blackberry Blossoms and Fruit
Blackberries are borne on the current year’s increase, with 10 to 20 flowers per cluster. Flowers bloom in early spring, or about mid-March in temperate climates. A blackberry is an aggregate fruit, composed person drupes that form the berry Flowers include multiple pistils and personal pistils form drupelets when they are fertilized. Each person pistil from the flower should be fertilized to get a well-formed berry because insufficient pollination results in small, flawed fruit and poor yields.
Improving Pollination
Pollination can be affected by poor weather hampering honeybees and injuring flowers, particularly when the shrubs bloom early in the season. Planting additional blackberries and other plants to draw bees will enhance the speed of pollination, while cross-pollination — pollen transferred from another plant of the same species or cultivar — improves fruit quality and yield. Plant several “Arapaho” blackberries or a compatible cultivar, like “Ouachita,” which has similar cultural requirements to “Arapaho.” Plant blackberries two to four feet apart to enhance cross-pollination opportunities.