Growing Blackberry in South Florida

Scientific Name: Rubus fruticosus

Common Names: bramble, blackberry, European blackberry, black heg, wild blackberry

Origin: Europe and Asia

Family: Rosaceae

Other plants in the Rosaceae family: blackberries, raspberries and strawberries, apricots, plums, cherries, apple

Climate: Blackberry grows best in temperate climates. We have some blackberry species that are native to Florida such as wild blackberry. However, wild blackberry does not have marketing characteristics due to some reasons such as small berries, lack of uniformity, low yield, and late maturation. Blackberry grows in USDA zones 8 and 9. Blackberry cultivars require 300 to 900 chill hours below 45 °F for bud break. If the plant does not receive sufficient chill hours, it shows poor bud break, and the plant will have a less fruit set. To check the chill hours in your area, visit Agriclimate (http://agroclimate.org/tools/Chill-Hours-Calculator/). Selecting low chill cultivars based on the chill hours in your area is necessary to have the optimum yield.

Cultivars: Although blackberry can be planted in Florida, lack of sufficient chill hours results in poor bud break and consequently low productivity. ‘Prime-Ark Freedom’ cultivar is recommended for medium to large farms due to its high yield. For U-pick operations, ‘Ouachita’ or ‘Osage’ are also good options.

Propagation: Blackberry can be propagated by stem cutting, root cutting, suckering, and tip layering. Commercial growers use stem and root cutting for blackberry propagation due to lower costs compared to other methods. In stem cutting, apical 4-6 inches of cane is used when it is succulent but still firm. Application of rooting hormone can improve rooting rate and efficiency. The preferable media for cutting are perlite, peat, or a mix of peat and sand under the mist system. Root cutting is the fastest way to propagate blackberry. In this method, roots are cut ¼–½ inch in diameter into 6-inch pieces. They can be planted in the pot or directly in the final location. Recommended time for planting roots for the best results is winter.

Flower: As mentioned earlier, blackberry needs certain number of chill hours for bud initiation. The flowers are produced in late spring and early summer on short racemes on the tips of the flowering laterals. Each flower is about 0.8–1.2 inches in diameter, with five white or pale pink petals.

Fertilizer: Blackberry roots grow close to the soil surface and excessive fertilizer may damage roots. In general, blackberry does not need much fertilizer. Fertilizer should be applied at least 18 inches far from the main stem to avoid damaging shallow roots. Fertilizer with N-P-K (10-10-10) with micronutrients is recommended for blackberry. Blackberry does not need any fertilizer during planting because the root system is not established yet. During root establishment, ¼ lb fertilizer can be applied in late spring or summer.

Irrigation: drip irrigation is recommended over overhead irrigation to minimize weed growth and reduce labor costs for weed control.

Weed control: It is very important to prevent weed spread on blackberry farms because weed control is difficult in blackberry and can easily get out of control. Weed control methods such as mulching, cultivation, herbicide, and mowing are recommended. The plastic mulch is highly effective in weed control in blackberry.

Pest and Disease: Several pests and diseases attack the blackberry. Insects such as the strawberry weevil, the red-necked cane borer, thrips, gall midges, stink bugs, and beetles. Some of these insects are occasional pests for blackberry and do not need control. Common diseases of blackberry are anthracnose, leaf spot, crown gall, rosette, and orange rust. Please contact your county Extension agent for current pesticides and rates.

For more information, please read:

https://edis.ifas.ufl.edu/publication/HS104

https://edis.ifas.ufl.edu/publication/HS1352