The easiest way to clone delicious blackberries is to use the tip-layering method. Tip-layering is a method of propagation used often for vine-growing plants, which involves planting the tip end of a still-growing vine into the ground to produce a new plant. Growing blackberries from cuttings is simple and economical, and this method will produce a great clone of your blackberry bush that will yield more blackberries in the next growing season.
Select a stem in August or early September that is healthy and strong and contains no marks, wounds or dead leaves. The stem should be long enough that its tip touches the ground easily when bent.
Dig a small, 15 cm (6 inch) deep hole that the top of the stem can reach when bent over.
Bend the stem over and stick it into the dug hole. Bury it with soil. Use small garden stones to surround the buried point of the stem to keep it from dislodging itself. In about two months, the buried stem will grow roots.
Cut the stem from the mother blackberry vine with pruning shears, making the cut 30 cm (1 foot) from the base of the rooted daughter vine.
Dig the rooted cutting up carefully, being sure not to damage its small, young root system.
Move the cutting into a pot filled with quality soil and keep it indoors or in a greenhouse until the following spring. Water the growing daughter plant regularly to keep its soil moist.
Transplant the daughter blackberry plant to its new permanent location in spring after the last frost of the season.