Blackberry plants, cousins to raspberry and strawberry plants, grow natively in North and South America, as well as Europe and Asia. Blackberry bushes protect themselves with hard thorns. Historically, they served as barriers to keep out attackers in Europe. Recently, plant breeders developed a few varieties without thorns. Whether called bushes, brambles, vines or briars, the blackberry plant produces fruit that has been harvested for eating and medicinal purposes for centuries. Propagate blackberry bushes easily from cuttings.
Mix one part peat moss to one part perlite and fill a flower pot with the mixture. When propagating the cuttings outside, combine the mixture with the soil in a bed instead of a pot. Work the soil well, so that it is thoroughly mixed.
Wear gloves to protect yourself from thorns. Snip a new-growth cutting from a healthy blackberry plant. Do this early in the year before the new growth becomes woody. Cut the cane 4 to 6 inches long, making sure there are leaves as well as buds on it.
Insert the cutting into the soil at least two inches. Position at least one bud under the soil and at least one leaf above it. Press the soil around the cane firmly and water moderately.
Cut the bottom from a plastic soda bottle and place it over the cutting. Leave the cap on the bottle. Press it into the soil so it forms a sturdy shelter for the cutting.
Place the pot in a warm location for five or six weeks. If you are propagating the plant outside, check that the plastic bottles are well seated, so they provide warmth for the canes and protect them from the wind and frost.
Check to see if there are new roots and new leaves on the cuttings in five or six weeks. If so, transplant them to the location you desire.
You can propagate an existing blackberry vine by bending over the newest canes and covering them with soil. Weight with rocks if necessary. When the new cane grows out of the soil in a few weeks, cut the original cane a few inches above the ground. You can then transplant the new vine. This technique is called layering.
Blackberry thorns are very sharp. Always wear gloves and long sleeves when working with the vines.