Blackberries are a perennial plant with fruiting canes that are biennial. The root system of the blackberry aids in the plant's propagation, along with the small seeds that can be spread from birds. Extending the plant's growth by digging it up and moving it to other areas is best performed in early spring. The exposed roots can easily dry out and should be soaked in a bucket of water for a few hours prior to replanting.
Wear the leather gloves prior to performing any work around the blackberry plant. The small thorns can embed into the skin and be extremely aggravating.
Cut the upper canes on the blackberry plant back to 6 inches in height with the pruning shears. Remove the spent canes to an area well away from the blackberry planting area.
Dig out the blackberry plant using the shovel. The hole must contain enough of the root system for a successful transplant. In general, create a hole that is approximately 12 inches to 16 inches in diameter and approximately 12 inches deep. This will maximize the amount of roots for the transplant. You will be cutting through some of the plants roots, but having a root ball that contains a majority of the root system will increase chances of the plant surviving.
Prepare the transplant hole by using the shovel. Make the transplant hole the same size as the root ball of the plant you removed in step 3 above.
Soak the transplant in a bucket of water for a few hours prior to planting it in the new location.
Move the root ball to the new hole. Set the plant into the hole so the old topsoil level is equal with the new location ground level. Tamp the plant gently into place with your foot.
Water the new transplant, with the garden hose, to remove any air that may surround the root system. Add approximately 2 inches of water per week for the first month, or until local rainfall will match this equivalent.
Add ammonium nitrate at a rate of 10 lbs. per acre, 1/4 lb. per 1,000 square feet, to the newly transplanted blackberry plants. This addition of fertilizer must be done after the plants have been established in the new location for at least four weeks to eight weeks. Do not add any fertilizer to the plants prior to this time. The blackberry plant must be established prior to any chemical fertilization.