Pruning vs. Training?

A long time ago, when I first started growing fruit trees and vines, I read a lot about the all-important pruning and training they require. But I couldn’t get clear on my head what exactly the difference was between “pruning” and “training.” I went on to learn that and a whole lot more about pruning (through books, as an ag researcher for Cornell University, and with practical experience), and eventually wrote my own book about pruning, hoping to present the techniques with more clarity and completeness than all the books I had read. Perhaps my book, The Pruning Book, does that.
Grape vine in spring
Okay, to answer my question of yore. “Training” is developing the young plant to a permanent framework that is sturdy and will always have its limbs bathed in light and air, and whose fruits hang within easy reach.

Kiwifruit within easy reach

Kiwifruit within easy reach

Training involves some pruning as well as coaxing stems to grow in certain directions. Once a fruit tree or vine’s training period ends, it generally only needs annual pruning.

Vine-y Training

I thought of all this today as I pruned hardy kiwifruit and grape vines. Both fruiting vines have been trained and are pruned similarly, with one slight variation that I’ll soon mention.

The kiwi and grape vines are trained as “double cordons” which are permanent arms sitting atop a trunk. They run in opposite directions along the middle wire of a 5-wire trellis, the wires parallel and supported about 6 feet of the ground on the cross-arms of T-posts. Each young vine was planted next to a metal or wooden stake to which the plant’s most vigorous stem was tied.

Once that trunk-to-be reached up to the middle wire, I tied it there and cut off all other stems. That trunk-to-be does, of course, keep growing; that new growth gets bent over and tied along the middle wire. Bending coaxes new buds to burst just beneath the bend, one of which is also bent over and trained along the middle wire in opposite direction to the first stem. Both these horizontal stems became the cordons, permanent arms of the plant. Growing off at right angles to the cordons are the fruiting shoots which, weighed down with their weight of fruit, drape onto the other wires.

Vine Maintenance

Today I’m maintenance pruning vines whose training period ended years ago. Maintenance pruning a mature fruiting vine keeps it bearing high quality fruit within easy reach year after year, all accomplished with a renewal method. That is, except for the trunk and the cordon, the vine is completely renewed with each year’s pruning.

I’ll admit it: A vine looks like a tangled mess before being pruned. But step by step, it  begins to take shape and make sense. Kiwi before pruning

Knowing how a plant bears fruit is important in maintenance pruning. Kiwi and grape vines bear on new shoots growing off one-year-old stems. Kiwis bear best if those one-year-old stems are about 18 inches long. Grape one-year-old stems can be left long or short, but for my method of training, I want each one about two buds long, which is just a few inches.

Fruiting grape shoots emerge from 1-yr-old stem

Fruiting grape shoots emerge from 1-yr-old stem

Step one is a no-brainer. The outermost wires are 4 feet apart so I lop all growth back to just beyond those wires. My tool of choice for this is a battery-powered hedge trimmer although pruning shears would also do the trick, except at a snail’s pace.First step in pruning

Step two is to remove excess growth, which does two things. It removes potential fruits so that more of the plant’s flavor-rich goodness gets funneled into those that remain, and it decongests the plant. For this step, I cut back all stems 2 years or older.

But wait! Two-year-old stems have one-year-old stems, the stems needed for bearing shoots, growing off of them. So rather than cut a two-year-old stem all the way back to its cordon, I cut it back to a one-year-old stem originating near the cordon. Some one-year-old stems also grow right from the cordon. The best one-year-old stems are those that are moderately vigorous and, of course, look healthy. Moderately vigorous stems, for grape or kiwi, are about pencil thick (if you can remember what a pencil looks like; if not, about 1/4” thick).

Kiwi stem and pruning detail

Kiwi stem and pruning detail

There will always be too many one-year-old stems for the plant to make tasty fruit. So I reduce the number of potential fruits by removing some of the one-year-old stems, enough to leave six to ten inches between them on each side of a cordon.

Pruned grapevine

Pruned grape vine

Pruned kiwi

Not finished yet. The final step is to shorten the fruiting shoots. For hardy kiwis, I cut them back to 18 to 24 inches long. For grapes, to about 2 buds or a few inches long.

Oh, one more thing to do: I prune off any new growth rising up from ground level or along the trunk lower than the cordons.

And one more thing: I step back to admire my handiwork. (Here is a video of me pruning a kiwi vine.)  

But What About Bushes?

You might have noticed, early on, that I wrote about pruning and training “fruit trees and vines.” What about blueberries, currants, gooseberries, elderberries, and other FRUITING BUSHES. Yes, they need annual pruning also. No, they do not need training. Although the plants are perennial, their stems are evanescent, all with a limited life. They are pruned by a renewal method — at ground level. All this and much, much more (pruning ornamental plants, houseplants; creating and caring for an espalier; how to scythe; etc) in The Pruning Book, of course.


Training Sessions

   Anyone appalled at the apparent brutality with which I approached my grape and kiwi vines a few weeks ago, pruning shears, saw, and lopper in hand, would have been further shocked today. But no harm done. (The kiwis are “hardy kiwis,” that is, Actinidia arguta and A. kolomikta; fuzzy kiwis are not cold-hardy here.)Well trained and  pruned grapes
    Left to their own devices, grape or kiwi vines would, every year, grow larger and larger, eventually, if once coming upon something to climb, sending their fruits further and further out of reach. Or, if not out of reach, then increasingly tangled in a mass of stems. In the dank interior of that mass of stems, many a grape would have rotted rather than ripened.
    Most importantly, though, grape or kiwi berries on untended vines don’t taste that good. Self-shading cuts down flavor-producing photosynthesis. And the plants’ energies must be spread among too many fruits; pruning limits yield but lets the plants pack more flavor into what fruit remains.
    The first thing I did, when I began pruning a few weeks ago, was re-organize the vines. Both bear fruits on new shoots growing off one-year-old canes. I train these plants on T-shaped trellises, with 5 wires stretched from T to T. A trunk rises to the height of the wires, at which point it bifurcates into cordons — permanent arms — each traveling in opposite directed up and down the middle wire. The one-year-old fruiting canes are splayed out perpendicularly to the cordons.
Fruiting shoot emerging from 1-year-old cane    Both vines grow prodigiously every year, the fruiting canes too long and too abundant. So I shortened all the canes to 3 to 4 feet long, which was just beyond the outer wires, and cut off those super-vigorous ones having stratospheric aspirations.
    Still too many canes: So I reduced their numbers. A couple of weeks ago, I went over the vines again, aiming (ideally) for one cane on either side of the cordon every 6 inches or so.

Round Three, of Pruning Grape & Kiwi

    The average date for the last killing frost here is around the third week in May. Evidently not so, this year, but I wanted to wait to do the final grape and kiwi pruning until after that date. The tips of the canes would be the first to grow and, hence, frosted, which is not a problem if the canes would anyway be shortened again.
    Now that frost is probably just a memory, I thinned out the canes one last time — to almost a foot apart — and further shortened those that remained. The grape canes got shortened to two buds each and the kiwi canes to about 18 inches long.

Grapes, In the Bags

    The next order of business, for just the grapes, will be bagging the bunches. I’ll wait until the berries have begun to swell and then partially slit the folds of delicatessen bags so that they can be slid over a bunch with the stem holding the bunch sliding into the slits. Each bunch has a leaf or a tendril opposite the bunch which needs to be clipped off so the top of the bag can be tightly folded over the stem, then stapled shut on either side, just below the slit.Bagging grapes
    To see rather than, or in addition to, read about bagging grapes, see my video.
    Why the bags? To keep diseases, birds, bees, and other insects at bay. With this protection, ripe bunches can be left hanging longer than usual to develop very rich, sweet flavor. Worst case scenario is that a bag is opened and there’s nothing inside. This sometimes happens. Best case scenario is peeling open a bag to reveal a perfect bunch of grapes with perfectly ambrosial flavor.

Hardy Kiwi, J’Accuse!

    I’m glad I planted the hardy kiwi vines many years ago because it may be illegal to do so in the future. Yes, illegal! No, not because you can smoke the plant, but because has raised eyebrows in certain invasive plant circles. Nonetheless, it’s a very attractive vine with very tasty fruits. And mine have remained well-behaved in the quarter of a century that they’ve been in the ground.
    In case fellow New Yorkers were not aware of this, as of March 10, 2015 it will no longer be legal to buy, sell or transport 126 species identified by the New York State Department of Environmental Conservation as invasive. Sixty-nine of these species are plants; hardy kiwi vines are not one of them — yet.
    I don’t doubt that there are plants that threaten to take over the world. Well, not the world, but certain ecosystems. Which is why garlic mustard, Japanese knotweed, and autumn olive are on that most unwanted list, despite their qualities. Autumn olive, for example, enriches the soil with nitrogen garnered from the air by symbiotic microorganism at its roots. Its flowers sweetly perfume the air in spring. And the small berries that ripen in early fall, if harvested as soon as they have lost their astringency, are rich in flavor and super-rich in healthful phytochemicals known as lycopenes.
    Hardy kiwifruit has not been banned anywhere, but in 2012 Massachusetts Audubon Society published an Invasive Plant Pest Alert strongly urging people not to grow or propagate this plant. Their statement was based on apparently rampant growth that was documented at two sites in Massachusetts and one in New York.
    The findings don’t jive with the good behavior of numerous vines that have graced gardens, as ornamentals, in Eastern U.S. since the late 1800s. Perhaps most of those planting included only female or only male plants, in which case no viable seeds would be produced, although the vines could also have spread by climbing trees or rooting where they touch ground under the right conditions.
    Male and female kiwi vines do socialize when grown for fruit in commercial and research plantings. But again, plants hardly, if ever, have multiplied on their own at these locations, which concurs with my observations here on the farmden.
    As a general rule, only 10 percent of any introduced species are likely to become established on foreign ground, and only 10 percent of those plants are likely to become invasive. Let’s be very careful in our condemnations and not blow the threat of invasive species out of proportion.

Plant Sale Saturday

This Saturday, May 30, 2015,  Permaculturesque Plant Sale at my New Paltz, NY farmden, from 10 am until 2 pm. Ornamental plants, edible plants, and ornamental AND edible plants such as 2 crop figs, hardy oranges (Poncirus), rosemary, dessert gooseberries, delicious and nutritious black currants, and much more.