How To Prune Jupiter Grapes

Four Arm Kniffin System for Growing Grapes

David Handley: I'm David Handley, vegetableand small fruit specialist with the University of Maine Cooperative Extension. Today we'regoing to be talking about a simple system for pruning hardy grapes here in Maine. The pruning system I like to use is very simple.It keeps the plant open, so it gets light in the summer time, but it also protects theplant a little bit in the winter. This system works best with concord type or labrusca typegrapes, which are the grapes that tend to grow best in Maine. There's really a couple of systems that willwork well for labrusca type grapes. The first

one I want to talk about is the four arm kniffin,and that's what we're going to prune first. The four arm kniffin consists of a perennialtrunk, which goes from the ground right up to a top wire, which is set at about fivefeet. Coming off of this trunk, we will have four arms, or canes, oneyear old growth.Two on the top wire, running each side of the top wire, and two on a lower wire. Thislower wire should be set at about two and a half feet off the ground. Every year, we're going to come in and pruneit so we continue to have a perennial trunk, but only four one yearold trunks to producethe fruit.

Here is our permanent trunk. You can see here,this is a cane from last year. Two yearold cane, this was our fruiting cane last summer,and you can see the difference. Here's this year's cane, that nice chocolate brown colorand smooth bark, and here we go with the older cane, the two yearold cane. The bark is startingto peel, and has more of a gray look to it, so we know that this particular shoot isn'tgoing to fruit again. It's the one yearold shoots that come off it that will fruit. This is going to get pruned out, so that wecan keep our fruiting wood closer to the trunk. We'll just take that back to a good fruitingshoot, and we'll start to cut it out. This

is where it gets fun. We need to wrestle thisout of the trellis, and of course, all these little tendrils have tied it up and aroundmost of the growth that's there. It takes a little bit of cutting, but be careful notto break the fruiting canes that you want to leave behind. Pull it off, and that will open the plantingup so we can see what we have left for good fruiting wood for this year. We've taken offthe four fruiting canes that we left last year, and you can see pretty much all that'sleft, at this point, is the green shoots from last year, that will provide us with goodfruit for this year.

Now we need to choose which four we want toput up. We're going to have four canes. One, two, three, four. Two for the lower wire,two for the upper wire, each heading off in different directions. What I want to look for in this case is canethat's got this nice chocolate brown color, and is about 38 of an inch in diameter. Aboutthe width of your little finger. If it's thinner than that, if it's very weak, it won't producegood fruit. Thin stuff like this, less than 38 of an inch in diameter, we'll just cutthat right out. Here we've got one that's going to go in thisdirection, that looks very nice. I'm going

to count, remember we want about 10 buds onit, so we'll count our buds. One, two, three, four, five, six, seven, eight, nine, 10. ThenI just cut out beyond that, because the weaker stuff at the very end isn't going to producevery good fruit. I have my four arms, but you can see I stillhave some leftover canes. What I'm going to use these for are what we call quot;renewal spurs.quot;I'm going to cut these back so that they just have one or two buds on them. What I'm goingto use these buds for, the green shoots that will emerge from these buds and grow out,will be the canes that I'll be putting on the wire next year for fruiting. We call thesequot;renewal spurs.quot;

Pruning Grape Vines

Hi, I'm Tricia, an organic gardener. If you want bunches of grapes on your grapevines this summer, then you need to do your winter pruning. I'll show you how! There are two types of pruning: cane and spur pruning. And both of them should be done late in the season, between January and March. We're gonna start with cane pruning, because all table grapeswill be productive with that method.

For cane pruning, I'm gonna choose one to two canesfrom last year's growth on each side of the vine and I'm going to cut the rest! You can tell the age of a cane by its bark. 1yearold canes have smooth bark,older canes have shaggy bark. When choosing which canes to keep, you're gonna choose a cane that's coming off very close to the trunk, as compared to onethat's coming off of a branch, like this. The canes that you keep should have about 15 buds along the length of the cane. And they should be close to the top of the vine.

Don't choose canes that are too thin or too thick. Choose them when they're about pencil size. I'm gonna tag the canes that I'm gonna keep with this ribbon, and I'm going to cut the rest. I want to make sure and not cut a good cane. These are the 2 fruiting canes that I'm going to keep. For every fruiting cane that I keep, I'm going to cut another cane into a renewal spur. A renewal spur is a cane cut to 2 buds and these buds are going to create next year's fruiting canes. If your cut starts to bleed, don't worry, that's normal. It won't hurt the vine.

After seeing how this vine is shaping up, I don't think I need this cane after all. So you're gonna cut your fruiting cane back to about 15 buds. And if you have any lateral branches coming off this cane, that's the time you would cut them. For grape vines growing on arbors, the first thing you're gonna do is cut off any suckers that are coming offthe main vine or cordon. And then you just want to cane prune. You want to keep one cane and one renewal spur for every 1 2 feet of cordon. This grapevine has been neglected and hasn't been pruned in a couple of years.

So, before I actually start the spur pruning, I'm going to clean it up. Typically, spur prune varieties are trained to a bilateral cordon, which are these thick branches on either side of the trunk. These cordons can be pruned to length, but they're never pruned all the way off, back to the trunk. Mine are maintained at about 3.5 feet. A spur is last year's growth, cut back to 2 buds. Ideally, you're gonna want 7 spurs on each cordon. And on this cordon, I'll probably get close.

On the other cordons, I'll have to wait until next year because this vine was neglected. The canes that make the best spurs are the ones that are going upward, close to the cordon. Prune all the canes to spurs and then select the best 7 for each cordon. Ideally the spurs should be spaced about 6 inches apart. Don't worry if they're not, just strive for some nice spacing between the 7 spurs on each cordon. Even though this is a nice cane, it's growing too far from the cordon, so I'm gonna snip it off. Tame your grapes and Grow Organic for Life!.

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