Grapevines must be pruned every year to remain fruitful. Any shivered fruit clusters remaining on the vines or trellises and all pruning waste must be removed from the vineyard during the dormant period and destroyed.
Grape pruning terms
- Cane—a mature woody shoot
- Cordon—a horizontal extension of the trunk trained along a trellis wire
- Lateral—side branch, either a shoot or cane
- Shoot—current season’s growth
- Spur—a cane pruned to 1 to 3 buds
- Trunk—vertical structure of the vine from the root system to fruit-bearing wood
Grape pruning tips
- Prune in March so you can determine the amount of winter damage. Leave more buds after particularly harsh winters.
- Typically, 90 percent of the previous year’s growth is removed during dormant pruning.
- Ignore the heavy sap flow from fresh pruning cuts made in late spring. This will not weaken or damage your canes.
- The sap may cause contact dermatitis in some individuals. Wear gloves when pruning.
- You can train your grapes to grow on arbors, fences, and trellises. On ornamental structures, prune for a longer trunk and leave more fruiting canes each year.
- For best fruit production, the “two-arm” system (illustration below) is the simplest to follow. This system supports the vine with a heavy (# 9) wire stretched between posts 60 inches above the ground. Use 7 ft. posts (3 to 4 inches in diameter) set 2 ft. into the ground 20 ft. apart. Nail or staple the wire to the top of the posts.
Pruning young grapevines
In early spring, select the best of the two original shoots to become the permanent trunk. Remove
the other one. Tie the young vine to a stake. As the vine grows, tie it to the wire. Cut it back right above where you tie it. This promotes straight trunk growth in the vine. Leave 4-6 buds near the top of the vine and remove the remainder. Remove any flower clusters from the developing lateral shoots.
In early spring, select the two strongest lateral shoots from each side of the trunk. Cut them back to 5 - 7 buds and tie them to the wire, extending in opposite directions. Select two other canes, one on either side of the trunk and cut back to 2 buds. These are called the renewal spurs.
Pruning mature grapevines
- Grapes produce fruit clusters on canes that are two years old.
- They are non-productive after they fruit and should be pruned out.
- The four shoots that grow from the two renewal spurs on either side of the trunk are also pruned.
- The strongest lateral cane on either side is pruned to 20 - 30 buds. These two laterals give you a total of 40 to 60 buds. The number of buds that you retain for fruiting is determined by the vigor of the vine.
- When the vine is weak, leave no more than 40 buds. Retain 60 or more if the vine is vigorous.
- The other two shoots are pruned to 2 to 3 buds and they become the renewal spurs. So each year you are removing the fruiting wood from the previous year and selecting new shoots (renewal spurs) to become next year’s fruiting wood.