Blackberry bushes flourish in the wild along roadsides with bushy thick vegetation, as well as in fields, near the ocean shore, in woodlands or on mountains. Wild blackberries are rich in vitamin C and can be made into jams, sauces, eaten fresh and chilled or tossed into desserts. Since wild blackberries grow tall and thorny, the arching canes need to be pruned to encourage future fruit harvest and to keep growth under control.
Wear gloves because blackberry plants are very thorny. Clear weeds from around the base of the plant.
Cut back and remove from the ground any blackberry plants within 2 feet of the plant so the area doesn't get too crowded.
Prune back any canes that are dead, broken or diseased first. Then cut back canes that are thinner than the others and appear weaker, as these canes won't produce fruit but suck energy from the healthier parts of the blackberry bush.
Prune with bypass pruners all first-year canes to 3 feet in midsummer. This encourages lateral branching on young plants. You can identify young blackberry plants because they only have one cane that is a couple feet tall.
Support the plant using a system such as a trellis or a stake. This will improve the chances of the plant surviving in the wild. Use twine to secure each lateral branch to the stake or system as it grows.
Cut back each lateral branch to half its length in late winter or early spring each year.
Prune off suckers with the pruning scissors. Suckers grow from the outside of the canes as small shoots that suck energy and nutrients from the rest of the blackberry plant. For larger blackberry plants, prune the remaining canes so they are no more than 7 feet tall.
Harvest blackberries when they are dark red to almost black. Then prune the canes to soil level.