David Handley: I'm David Handley, with the University of Maine Cooperative Extension,
and we're here to talk about pruning grapes.
Very simple system for far-northern production.
Here in Maine, we need to protect the vines as best we can through the winter, but at
the same time try to get enough light and exposure to the canes that we're going to
get good fruit set, and good fruit quality.
One of the systems you can use for labrusca type or concord type grapes, which are the
ones that do best here in Maine, which is the umbrella kniffin.
As opposed to the four arm kniffin, the umbrella kniffin puts all of its canes up at the top,
or the first year growth that's going to fruit.
What we're talking about with cane growth here is one year-old growth that has a chocolate
brown color, and nice smooth bark with buds on it.
We're going to be saving four canes, plus the permanent trunk, to give us all of our
fruiting structure.
Everything else is going to be coming off of here, and that includes anything that fruited
last year.
You can tell the two year-old canes, or the canes that fruited last year, because they'll
be thicker, and they'll have gray, peeling bark.
All of these are going to come off, and we're going to save the one year-old cane with the
chocolate brown color, and the smooth bark.
The first step in pruning is to look at our permanent trunk and remove all of the two
year-old growth, the growth that fruited last year, saving a few canes that we'll be using
for fruiting this year.
Our first step is to cut some of these off, looking at that older bark there.
We just cut that out, get it right out of there.
This will open up the planting, and that two year-old wood is not going to fruit.
Unless we take it out, we'll find that our fruiting wood gets further and further away
from the trunk.
Part of the reason we're pruning is to keep that fruiting wood concentrated right near
the trunk.
With the umbrella kniffin, which is what we're pruning to here, we're only going to maintain
four of those fruiting canes.
We want them all concentrated near the top of the trunk, or the top wire on our two-wire
trellis.
We're going to take each of the canes that remain behind.
As you can see here, here's my nice fruiting cane, smooth bark.
All these are buds that are going to break and give us long, green shoots that will have
bunches of grapes on them.
We're going to drape them over the top wire, and then we're going to attach them to the
bottom wire, to give you that kind of "umbrella" look, thus the name of the system called the
"umbrella kniffin."
Then we're going to cut off the ends of the canes, so that there's only about 10 buds
on each one.
We just count those from the trunk.
One, two, three, four, five, six, seven, eight, nine, 10.
If I need to leave one or two on there to make it reach the bottom wire, that's fine.
I'll just go to where I can attach this to the bottom wire, like that.
I need two for the other side, to complete our umbrella.
You can see this leaves me with several other fruiting canes, and I need to save some of
those as well, but they don't need to be as long.
What I'm calling these are "renewal spurs," because we need the buds from these shoots
to come out and give us cane that we'll be able to put up on the wire next year.
For every fruiting cane that I'm leaving behind, I also need to cut some renewal cane, or renewal
spurs, to provide us with fruiting wood for next year.
I just cut these back to one or two buds, and if they're not where I want them I can
cut them off completely.
But for every fruiting cane, I need to leave at least one renewal spur.
I tend to leave a couple of extra renewal spurs here in Maine, because I'm very sensitive
to the fact that I'm likely to get winter injury almost every year.
We'll just tie these to the lower wire.
A little bit of winter injury on that one.
You'll be able to see that we've got our umbrella.
We have our permanent trunk running up to the top wire, and coming off the top of the
trunk I select four one year-old canes, and I reach those over the top wire, and tie them
to the bottom wire, spreading them out a little bit to get that umbrella look.
This will provide plenty of light and air movement through the planting, as those shoots
start to develop and develop fruit, and also support the bunches of fruit, and make it
easy to harvest at the same time.
For every cane that I have over the wire, I need to leave a renewal spur or two, with
just one or two buds on it, because the shoots coming out from these buds are going to provide
us with our one year-old cane to put over the wires next year.
We do this every year during the dormant period, so any time pretty much from new years until
they start to bud out in early April is a good time to start pruning.
Anything you've cut out of the plant needs to be dragged out of the planting, chopped
up, put in your compost pile, into the burn pile, or just taken out so that it isn't a
source of potential for next year.
Prune every year, open those grapes up, hit them hard so lots of light will come through
there, you'll have a good crop of grapes, winter permitting.