Will Grape Vines and Blackberry Vines Mix If Close Together?

Pollination Issues

• Grapes and blackberries are not closely related plants. They cannot interbreed and their flower pollen will not affect the production of each other's fruits. Plant spacing and intermingling of branches plays no role in pollination of their flowers and potential fruit production. However, if one plant is shaded and choked out by the other, the number of flowers and subsequent fruits produced can be greatly diminished on the plant not receiving any sun rays.

Pruning Maintenance

• Proper annual pruning keeps both grape and raspberry plants types tidy and growing new stems that yield flowers and fruits. Grapevines are pruned back to central, main vines so only a few small buds sprout each spring to create larger, more flavorful grapes. Blackberry canes live for two years -- a cane develops and grows the first year and blooms and fruits the next. The cane dies after fruiting, but the roots always sprout new canes each year. For the best fruit production, the old canes that just fruited and are destined to die must be pruned out to allow the new and 1-year-old canes to prosper and produce in the future.

Spacing

• When a vineyard is planted, grapevines are planted 8 to 20 feet apart from each other in a row, with rows spaced 10 to 20 feet apart. If trained on a trellis, grapevines do not sprawl and take over wide expanses of the garden. Blackberries are either trailing/arching or semi-erect in form. Trailing canes are maintained at 6 to 8 feet long, while semi-erect canes are pruned to 5 to 6 feet long. Leafy twigs sprout from the canes and will arch on the ground until tied to a trellis or post. Space blackberries 5 to 10 feet apart.

Recommendation

• Unmanaged grapevines and blackberry thickets will crowd each other out if planted closely to each other. Pruning maintenance limits the random and uncontrollable growth and mess of stems to an extent. Grow both grapes and blackberries on trellises to control their stem orientation and facilitate access to plants. Ideally, do not plant grapevines and blackberries within 15 feet of each other to avoid intermingling of branches.