In general, vines of American grapes grow in flowing curtains that weep downward like a willow tree, and French grapevines grow more upright, like tomato vines. For all vines, new growth originates from shoots. Shoots grow from nodes (the areas of buds along the branches of the vines). Canes are branches that grew the previous year from a one-node spur on the cordon, the horizontal arms of the vine.
When you prune, you want to keep evenly spaced canes for growing the current year's crop, and about twice as many spurs to grow canes for next year's crop. French varietals are pruned to remove all growth points that aren't on the top of the cane. Because American vines grow downward, growth points are allowed to emanate from the top, sides and bottom of the horizontal cordon.
To begin winter pruning:
- Start at the trunk and move outward, removing dead canes.
- Next, remove canes that branch from another cane. Keep canes that originate from the cordon.
- Count your remaining canes. The number you keep on each cordon depends on varietal and maturity.
- Select healthy, evenly spaced canes for this year's growth. Trim each to three to five nodes (depending on varietal), leaving 1/2 inch (1.25 centimeters) of cane below the last node.
- Select evenly spaced spurs. Prune them to one node extending from the cordon.
- Cut extra canes flush with the cordon.
You can't prune vines without the proper tools, so read on to the next page to learn about them.