Do Grapevines Have Unnecessary Vines?

Main Trunk and Branches

• The main trunk of the grapevine should be allowed to mature and grow against a pergola, arbor or trellis to support its weight and the weight of its shoots. It should be pruned so it has no branches shooting off below 30 inches from the ground, and it should have only two main branches. If you're using the high-cordon pruning system, the vine should have one set of branches at the 30-inch point and another at 60 inches.

Ground Vines

• Any secondary vines growing from the trunk below the first main branch should be pruned back as soon as they are found. Vines growing too close to the ground are not only a drain on the vine with no possibility of fruit production, but they can also act as a "stepping stone" for insects and vermin. Prune these vines back clean against the trunk.

Secondary Branch Cordon

• The main branches of your grapevine are those that are connected directly to the grapevine's trunk. These should be trained on wire or a trellis at the 30-inch and 60-inch heights. The secondary branches, or the ones that will bear fruit in future seasons, are those that come off these main branches. These should be trained to hang beneath the wire or trellis upon which you have secured the main branches. No offshoots from these vines should be permitted to grow.

Nonfruit Producing

• If you are growing a grapevine for the purpose of shade, or just for the attractive green foliage, your vine can be allowed to grow fuller, and less care can be taken when pruning. Nonetheless, to prevent disease, and mold and mildew growth, your vine should be pruned seasonally to enable sufficient airflow. A good rule of thumb is to not overlap any branches, and never layer vines. Prune back foliage if it is not exposed to sunlight, and dispose of the clippings far away from the main vine to prevent the spread of any disease.