A Bold Experiment in Vineyard Pruning

Raindrops glistening along the trellis wires in the vineyard with the horses in the background.  This is the best I could do to make the rain look pretty.
Raindrops glistening along the trellis wires in the vineyard with the horses in the background. This is the best I could do to make the rain look pretty.

I apologize for the long silence but it’s been raining for so long and life on the farm has gotten so soggy, muddy and unattractive, it’s left me uninspired. But then, the clocks turned forward, the sun came out, and the farm came to life.  And just in time for the arrival of spring, the winter pruning in the vineyard is done!

A bud growing on "second year wood."  This was a green shoot with leaves and grapes during the last growing season.
A bud growing on “second year wood.” This was a green shoot with leaves and grapes during the last growing season.

For those who don’t know, grape vines must be pruned each winter.  The fruit comes from what is known as “second year wood,” or from the buds that formed on last season’s green shoots.  The trouble is, there are far more buds than you want because if all of that fruit developed, nothing would ripen.  So you have to prune it back to about 16-20 bud per vine, give or take, to get a good crop.

Winter vines in desperate need of a haircut.
Winter vines in desperate need of a haircut.

There is nothing more nerve-wracking than confronting a tangled mass of vines and trying to decide what to leave and what to prune.  Because once you make a cut, that shoot is gone!  Complicating matters even more is the fact that there are two general types of pruning to choose from, cane pruning and cordon pruning.

An example of a cordon pruned vine.  The arms, or cordons, will stay year after year, and like the trunk, will get thicker as the vine ages.
An example of a cordon pruned vine. The short branches sticking upward are the two-bud spurs. The arms, or cordons, will stay year after year, and only the growth out of the spurs is pruned. Like the trunk, the cordons will get thicker as the vine ages.

So before you can even start cutting,  you have to decide between cordon and cane.  Cordon pruning lays out an “arm” along the fruiting wire that stays there year after year.  The shoots grow out of buds on the little “spurs” from last year’s growth that you leave when you prune.  The goal is to give each arm 4-5 two-bud spurs.

An Example of our cane pruned vines.
An Example of some of our vines with two canes per vine. They look a lot like cordon pruned vines at the start. The difference is we will cut those canes off next winter and lay down new ones.

With cane pruning, you cut off the arm each year and lay down a new one from last year’s shoots.  Most growers lay out two arms per vine, one on each side, with about 6-10 buds each.  Less common is the “Uni-cane,” where you lay out just one long cane on one side of each vine that hopefully has about 18-20 healthy buds on it.

Nathan studies a cordon laid down last winter before cutting last year's growth down to two-bud spurs.
Nathan confronts cordons laid down last winter before cutting last year’s growth down to two-bud spurs. Once the cordons are established, this is a quicker and easier pruning method than cane pruning.

In our vineyard, we have decided to embark upon a bold experiment.  Our first planting of five acres is cordon pruned and the second planting of eight acres is cane pruned.  And I can’t tell you how controversial this is.  Nobody we know of in our part of Oregon does cordon pruning on their Pinot Noir vines.  The worry is that with all of our morning fog,  the buds left on the spurs were too low on last year’s shoots to get adequate sunlight.  And sunlight determines how “fruitful” the buds will be, or how much fruit they produce and how good it will be.

A close look at a two-bud spur on the cordon. As you can see, the buds grew low in the canopy last season, and so had more leaf cover and less sun than the buds that grew near the top of the shoot.
A close look at a two-bud spur on the cordon. As you can see, the buds grew low in the canopy last season, and so had more leaf cover and less sun than the buds that grew near the top of the shoot.

This is a valid worry.  We don’t get as much sun here as they do in Burgundy, France, where Pinot Noir comes from and where almost all the vines are cordon pruned.  But the thing is, nobody here has tried it to see what would happen. And so against the cautions, objections, and even outrage of some of our grape-growing neighbors, we are giving it a try.  Since most vineyards here drop upwards of half their fruit each year to be sure to ripen the rest, producing less fruit in the first place seems like a smart idea.  So the real test here is the quality of the fruit produced.

An example of a uni-cane vine with just one long arm laid down along the fruiting wire. This cane will be pruned away next winter and replaced with a new one.
An example of a uni-cane vine with just one long arm laid down along the fruiting wire. This cane will be pruned away next winter and replaced with a new one.

As if that isn’t excitement enough for one vineyard, we are experimenting with our cane pruned vines as well by going with the seldom seen “uni-cane.”  This is all about disease control.  Our theory is that by eliminating the overlap of shoots that grow at the point where the two canes from neighboring vines meet on the wire, we will get more air flow through our canopy (leaves and shoots) during the growing season and that will mean less moisture problems like Powdery Mildew.

Uma supervises Nathan as he ties down a new cane to the fruiting wire.  Tying down the canes assures they grow straight and the buds are pointed upwards.
Uma supervises Nathan as he ties down a new cane to the fruiting wire. Tying down the canes assures they grow straight and most of the buds point upwards.

Of course, that means longer canes, and more fruit from the buds near the very tip of last year’s shoots.  Those buds were the last to develop, leaving them with less time to soak up the sun during the growing season.  And so, the same concerns about fruitfulness apply.  We will have to see if the quality of the fruit suffers from having one long cane rather than two shorter canes.

Nathan strikes a "Jethro Tull" pose as he bends a new cordon along the wire.
Nathan strikes a “Jethro Tull” pose as he bends a new cordon along the wire.

Our vines are quite young, so it could be a few growing seasons before they start producing a consistent crop and we know  which method gives us the best fruit.  We may even have to produce wines exclusively from each pruning method before we know the results. If we are making a mistake with either of these pruning methods, it will take us years to correct it. I think that’s why our neighbors are so concerned. But that’s just part of the adventure.

The crew is working hard to finish tying down all the cordons and canes before bud break.
The crew is working hard to finish tying down all the cordons and canes before bud break.

For now, we wait for bud break.  Most of the vineyard is in the “wolly bud” stage, which means the hard outer shells on the buds have cracked revealing the white, fuzzy fibers inside.  You can see what a “wolly bud” looks like in the “second year wood” photo up top. If our warm weather holds, the shoots will start pushing against those fibers and we could see our first leaves in about 10-12 days.  I will post lots of baby pictures just as soon as the buds break.

Grey Kitty and Orange Kitty are very glad the sun finally came out!
Grey Kitty and Orange Kitty are unimpressed with the pruning activity in the vineyard, but they are very glad the sun finally came out!

2 thoughts on “A Bold Experiment in Vineyard Pruning”

  1. I never knew any of this. I have been awful about pruning my muscadines, and wondering why I haven’t gotten much fruit. I was blaming it on the birds! It is still not too late here for me to do some cutting back, but I can readily see that I have much to learn and lots of correcting ahead of me. Thank you for including so much detail in your post.

  2. You’re welcome. I am a newbie, but feel free to ask questions. I will do my best to answer. And Nathan is 4th generation Napa Valley winemaker/grape grower. If I don’t know, he will! The birds will get you, too. But when the fruit is ripening in the fall and they are migrating. More on that this fall!

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