Blackberries are a bramble plant that prefers to grow in a nutrient rich soil that does not hold excess water. The blackberry cane produces well when the summer temperatures are hot during fruit production. Blackberry canes winter over in climates where the temperature is above -10 degrees Fahrenheit. The propagation process to produce additional blackberry plants includes planting a stem cutting, root cutting or sucker growth.
Propagate a blackberry canes with stem cuttings by clipping off a 6-inch section of new stem growth in late spring to mid-summer. Dip the lower cut end of the cane in a rooting hormone to stimulate root production and speed the propagation process. Immediately stick the lower cut end of the cane into a tray filled with a moist propagation medium and place a clear plastic cover on top. Set the propagation in a warm area with a temperature of 68 to 70 degrees Fahrenheit. Open the tray each day and mist the stem and medium to keep the environment moist, but not wet. Roots will form in two to four weeks until optimal conditions.
An easy process of propagating new blackberry plants is removing soil around the main stem and clipping off a section of the root ball. Propagate a root cutting once the blackberry goes into the dormant stage in late fall to early winter to prevent damage to the plant or reduce fruit production. Set the propagated cutting into a planting hole that is slightly deeper than the clipping was originally growing. Monitor the root cuttings in spring to make sure the soil remains moist, not wet, around the new plants. This will stimulate root establishment.
Quick blackberry plant propagation involves removing the suckers that grow from the soil around the base of the plant during the summer growing season. Suckers have a root system and will establish quickly when planted in a garden bed. Remove the sucker shoots by digging around the sucker plant and clipping the roots off the main stem at the point of attachment. Plant the propagated suckers in a hole that is slightly deeper than the sucker was previously growing. Water the new blackberry plant well during the dry summer months to keep the soil evenly moist and stimulate root establishment before the winter months.
University of Florida: Blackberry and Raspberry
North Carolina State University: Plant Propagation for the Home Garden