Pruning grapevines is an essential step to having healthy vines. Pruning should be regular to encourage new growth. There are two main methods for pruning your vines – Spur and Cane pruning. Choosing the right method depends on what kind of grapevine you have planted in your garden.
For most European and muscadine grapes, excluding Thompson Seedless and Lady Finger, use Spur Pruning. With this method, you cut back your dead growth to create short “spurs” where the new growth will start. These spurs should have one to “canes” where the fruit and leaves will grow. Once the fruit is born and harvested, the canes will be cut back so new spurs will grow.
Use the Cane Pruning method for Thompson Seedless, Lady Finger, Concord, and Niagra grapevines. These vines rely on buds on the far ends of their canes to produce fruit, thus, if they are cut to spurs, their production will suffer.
There are specific steps you must take each season to grow your grapes into a mature plant. For the first three growing seasons, the steps are the same. In the third dormant season, the methods of spur and cane pruning will come into play.
In the first growing season, plant your vine and let it grow as it chooses. A healthy vine will grow several shoots.
In the first dormant season, during the winter, choose the best shoot, which is usually the thickest, and prune all the others around it to the base of the vine. Make sure you have your trellis buried close to this shoot to guide it’s growth. This will be the trunk of your vine.
In the second growing season, let the shoots grow to about 12 inches long. Choose the healthiest shoot, often larger in diameter and closer to the trunk, and pinch off the others where they connect to the trunk. Tie the one shoot to the support and guide it to grow upward toward your wire. Once it is close to the wire, pinch it to stimulate branching. Let another strong shoot near close to the wire branch on the other side, so your vine begins to grow in a T shape. These will become your main branches. Pinch off all the others that are 8-10 inches long.
In the second dormant season, cut away all the shoots to leave only the trunk, and the two main branches. Tie the branches to the trellis wire.
In the third growing season, let the vine grow, pinching the tips of sprouts on the trunk to stimulate growth.
Spur Pruning – Third Dormant Season and Beyond
In the third dormant season, cut away all shoots that have grown on the trunk. On your two main branches, find the strongest shoots. Prune the shoot so that everything but two buds on the branch are removed. These will be your spurs. Space the spurs out 6-10 inches, making sure every spur has two buds. If there are weak shoots at the base, prune these away.
Your grapevine will be established by now, so every dormant season after this will be the same. Each spur will produce two shoots that bear fruit during the growing season. Prune away the weak spurs, while cutting the stronger spurs down to two or three buds, which will produce fruit in the summer. Keep the trunk clear of any new shoots. Repeat this process every year.
Cane Pruning – Third Dormant Season and Beyond
In the third dormant season, cut away all shoots that have grown on the trunk. Prune everything but two long shoots off the two main branches. These two shoots that remain are usually closer to the trunk because they are the healthier shoots. The shoot that is farther from the trunk should be tied to the wire. Prune the farther shoot to two or three buds. The shoot that is tied to the wire will bear the fruit in the next season, while the shoot you clipped will grow to replace the tied shoot and produce fruit the season after next.
Every year after this, prune the cane that produced fruit to the stub, which should have two or three canes growing off it. Choose the best cane and tie it to the wire – this cane will produce the fruit the next season. The weakest shoot should be removed at the base of the shoot, so there are only two canes left. The cane that is not tied to the trellis should be pruned to two or three buds, to prepare it for bearing fruit the year after next. Repeat this process each year.