Gadenin日本語Get the appWhy you cut off so much
A grape flowers on the current season's shoots, and those shoots only carry fruit when they come from wood that grew last year. Wood two years old and older is plumbing: it moves sap and holds the vine up, but it will not fruit. That single fact is the whole logic of grape pruning. Every winter you keep a small ration of one-year-old wood and cut the rest away.
An unpruned vine is not a bigger crop. It puts out a tangle of shoots that shade one another, the fruit sits in gloom and never sweetens, mildew spreads through still air, and the fruiting zone marches further from the trunk every year until the productive wood is up in the gutter. Cutting hard is not a punishment, it is how you keep the crop within reach and in the light.
| Wood age | How to recognize it | Does it fruit |
|---|---|---|
| Current season shoot | Green, soft, still growing | Carries this year's bunches |
| One-year-old cane | Smooth, tan to brown, buds along it | Its buds give next year's fruiting shoots |
| Two years and older | Gray, shaggy, peeling bark | No, structure only |
Prune in the depths of dormancy
Prune in the middle of the dormant season, after the vine has been fully leafless for several weeks and before the sap starts to move. Cut too late and the vine bleeds clear sap from every wound for days. Bleeding rarely kills a vine but it delays bud break and the wet wood invites infection, so it is worth avoiding.
In gardens with hard winters, hold off until the worst cold has passed, because pruned wood is slightly more prone to freeze damage at the cuts. In mild gardens the vine may barely go dormant at all; use leaf fall as your signal and prune four to six weeks after it. Never prune in autumn while leaves are still feeding the roots.
If you find yourself pruning late and the vine bleeds, do not bandage or seal the cuts. Sealing traps moisture. The bleeding stops on its own once leaves open and start pulling water through.
Spur pruning: two permanent arms and short stubs
Spur pruning is the simpler system and suits most garden vines. You keep a permanent trunk and two permanent arms along a wire. Along the top of each arm sit short spurs spaced about six inches (15 cm) apart, and each winter you cut last year's canes on those spurs back to two buds. Those two buds give you two fruiting shoots next summer.
The discipline is in refusing to let spurs get long. Each year the spur creeps outward by an inch or so, and after five years the fruiting wood stands a foot off the arm on a knuckly stump. When that happens, look for a shoot growing directly from the arm near the base of the old spur and cut back to it, resetting the spur to the wire.
- Clear the obvious first Cut away everything dead, broken or thinner than a pencil, plus every shoot growing from the trunk below the arms. This alone removes most of the confusion and lets you see the framework.
- Identify each spur position Work along one arm and find the short stubs, roughly a hand's width apart. Anything growing between them that does not sit on a spur is surplus and comes off flush.
- Choose one cane per spur Each spur usually carries two canes from last summer. Keep the lower, thicker one, ideally the one nearer the arm, and remove the other completely.
- Cut to two buds Shorten the kept cane so two fat buds remain, cutting about an inch (2.5 cm) above the upper bud. Count buds, not length; buds near the base of a cane are sometimes crowded together.
- Renew any long spur Where a spur has crept more than four inches (10 cm) from the arm, cut the whole thing back to a low replacement shoot at its base. If there is no replacement, cut it right off and let a new shoot fill the gap next summer.
| Vine vigor | Buds per spur | Spurs per arm |
|---|---|---|
| Weak, thin canes | One or two | Four to five |
| Average | Two | Five to seven |
| Very vigorous, thick canes | Two or three | Seven to nine |
Cane pruning: replace the fruiting wood every year
Some vines set little fruit from the buds nearest the base of a cane, and spur pruning on those vines gives leaves and no bunches. The answer is cane pruning: instead of short spurs you keep two whole canes of eight to twelve buds each, tie them along the wire, and cut everything else away. Next winter those canes come off entirely and two new ones replace them.
The trick is to leave a renewal spur beside each cane. Cut a second shoot near the head of the vine back to two buds; it produces the canes you will tie down the following winter. Without renewal spurs the fruiting position climbs a foot further out each year and the vine outgrows its wires within a few seasons.
- Pick the canes before you cut anything Choose two canes of pencil thickness or a little more, growing close to the head of the trunk, with smooth brown bark and short gaps between the buds. Mark them with a loop of string.
- Leave two renewal spurs Choose two more shoots near the head and cut each to two buds. These are not for fruit; they are the source of next winter's canes.
- Remove everything else Cut away all remaining canes flush with the arm or the trunk. A cane-pruned vine in winter looks almost bare, which is correct.
- Shorten and tie down the keepers Cut each kept cane to eight to twelve buds and tie it horizontally along the wire, using several loose ties. Bending the cane down evens out the sap flow so buds break along its whole length rather than only at the tip.
Horizontal really matters. A cane tied at an angle pushes its strongest shoots from the high end and the buds near the trunk stay dormant, leaving a bare stretch you can never fill.
Summer pruning keeps light on the fruit
Winter pruning sets the crop; summer pruning ripens it. Once shoots reach about eighteen inches (45 cm), thin them so the remaining shoots stand roughly a hand's width apart along the arm or cane. Crowded shoots shade each other's leaves and trap humid air around the bunches.
Stop each fruiting shoot at two leaves beyond the last bunch once the fruit has set. This diverts energy from tip growth into the fruit and keeps the canopy open. Side shoots that spring from the leaf joints afterwards can be pinched to one leaf; do not strip them entirely, because the leaves nearest the bunch supply most of its sugar.
Pull leaves directly shading the bunches only as ripening begins, and only on the morning side of the row. Stripping the afternoon side exposes the fruit to scorch, which shows as sunken tan patches on the berries that never recover.
Keep a note of what you cut
After each winter pruning, write down how many spurs or canes you left on each vine and how many buds in total. Next autumn, compare that number against the crop you actually got and the thickness of the canes that grew. Thin, whippy canes mean you left too many buds; a forest of thumb-thick canes with little fruit means you left too few.
Two or three seasons of that record tells you the right bud number for your soil and your site more accurately than any general rule, and it is the fastest route to a vine that crops the same amount every year instead of alternating between glut and nothing.