Prune, Remove, Repeat

By Karl Klooster

When harvest is over and the leaves fall from the vine, industry emphasis turns to making the wine and reflecting on the vintage just completed. For vineyard managers—viticulturists—the hard work of the season is done. But only temporarily.

A grower might contemplate the possibility of taking off a couple weeks, spending a little down time in some warmer clime. But to actually do that takes pre-planning, particularly for those who are hands on.

The vines may go dormant for a few months but therein lies the need to take essential actions that will protect the vineyard during the harsh weather it will have to endure in coming months and the opportunity to prepare it for the next season.

Here in Western Oregon, winters are not nearly as cold as in the east or even in Eastern Washington, where mounding of earth around the base of the vine trunk helps protect it from the possibility of permanent damage.

But since it does rain here, steps to reduce soil erosion are important, particularly on steeply sloping sites. This work can be difficult and even dangerous.

Sometimes rain-soaked soil is too soft and slippery for tractors to operate safely. Between-row maintenance can be only done when several drier days present themselves.

It’s no time to be basking in the Bahamas unless you’ve got someone else behind the wheel who knows what he or she is doing.

No matter where they’re located, vineyards must be closely assessed after each harvest for diseases and other problems whose symptoms can be best determined this time of year.

Soil analysis and vine inspection can detect deficiencies and point to appropriate measures such as compost spreading and the addition of nutrients. Seeding of cover crops will aid water penetration and help control erosion.

Once the foliage is gone, the bones of the vine, so to speak, are exposed. This basic structure—trunk, cordon, upright canes—tell the grower the age and health of the vine.

Most importantly, the buds that will become the fruiting canes for the next vintage have sprouted from those of the current one. These tiny nodes are the essential element without which nothing else would matter.

If all the shoots from the previous year were cut off, there would be no grapes the following year. Obviously, vine tenders have to know what they’re doing because about 90 percent of the growth is removed in the pruning process that involves several steps between December and March.

When last year’s brush has been cut away and mounded in the rows, it can be totally removed or partially mulched in when mowing. Cuttings for grafting or nursery propagation of new vines can also be gathered at this time.

Ecological practices call for bundling and recycling of the discarded materials with green waste.

Machines have been developed to harvest grapes and their sophistication continues to improve. But no one has yet designed a machine that can properly prune a grapevine. This can be done only by skillfully executed hand labor.

Most premium vitis vinifera grape varieties—Pinot Noir, Chardonnay, Pinot Gris, Riesling, etc.—are ultimately pruned back to just two shoots on which the fruiting buds for the next vintage will grow. However, in cold climates and on sites prone to spring frost, more buds are retained to compensate for winter damage or severe frost conditions at bud break.

Depending on how things turn out, during the second pruning, supplementary canes are removed or spurred—trimmed back to the base—and excess buds are cut off, usually leaving just two buds. Specifically, when and how much is up to the viticulturist. Some early ripening varieties require initial pruning in January while completion of some that are more susceptible to bud damage may not be done until March.

To avoid wind damage, the cordons are then tied down horizontally to the lowest wire on the trellis and pruned so that shoots don’t cross between plants. Young, closely spaced or densely plated vines are often pruned to one shoot. 

Other winter tasks include vineyard infrastructure replacement and repair, primarily broken or deteriorated posts and snapped trellis wires. If new plantings are part of the plan, new posts and trellises need to be purchased and an order placed with nurseries for new vines. In general, planning for the next season is finalized during these contemplative months.

Is it time to re-plant? Do we want to expand the vineyard? Change varietals? Will what we did this season work as well next season? And the one after? Is there some piece of equipment or a technique that will work better?

One grower summarized, in general terms, the ideal goal behind all the work that goes into the year-round regimen is designed to grow the best possible grapevines and resulting fruit. 

Thinking from a viticulturist’s perspective, it is said that when they look at a vineyard they see bottles of wine. Each bud is like a glass. It contains a shoot that will produce one to three clusters of grapes.

When pruned, each vine in a mature vineyard that yields concentrated, flavorful grapes will produce only 12 to 15 buds. The grapes from each vine will result in only one to two bottles of wine.

Remember, the viticulturist loves to grow grapes but he loves what they make just as much. Maybe even more. 

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