Pruning-Cordon Placement Question.

Masbustelo · Sep 10, 2016

I have a pruning-cordon placement question. These are first year Petite Pearl vines. The top of the arbor is ten feet off the ground. I plan to have a top cordon at the ten foot level, and the vines are beginning to send out various laterals. I assume I can also have parallel cordons at the five foot level. What is the minimum height off the ground for cordons? Could I have three sets? Like at three feet, six feet and then ten? I don't plan on doing any pruning until next spring. I am in Illinois

TonyR · Sep 10, 2016

You can try. My Petite Pearl are not that vigorous. My vines are 6 years old and maybe 1 inch at the base of the vine.

dbeck · Sep 10, 2016

You can only put so much fruit on a vine and multiple levels of cordons seems a bit excessive to me. You might consider putting your cordons at about 6 feet and then letting your fruit hang down from there same as if you were using a high cordon trellising system.

GreginND · Sep 16, 2016

With this tight spacing, I would think you can crop fine with two sets of cordons. I would not push it to three. But a mid and high cordon is unusual. You would likely have to grow both layers downward. Thus, your top cordon at 10 feet will shade the lower cordons and the grapes will not ripen as well.

You might want to consider a 4 arm kniffen system. In this system you grow four cordons one set just above the other. The lower cordons have shoots trained downward while the cordon just above it have the shoots trained upwards like a VSP. That way the fruiting zone gets maximum sunlight.

But your vines may be ok the way you have it. Just be cautious about shading your lower fruit.

Masbustelo · Sep 17, 2016

Thanks Greg The trellis is on the South side and is really bathed is sun all day long. I'll have to check it closely, but I don't think it casts shadows. It runs East-West. Would I leave the existing "cordons", and tip them in the spring? Or cut them back and regrow them? If I did the 4-arm kniffin how far apart would I space the cordons?

garymc · Sep 17, 2016

Having cordons low, say at 3 feet leaves them close to the ground, humidity, insects, and if you spray herbicides to keep weeds and grass at bay, that low foliage might get some spray. Then stooping or crawling on the ground to harvest grapes is not my favorite activity.

Masbustelo · Sep 17, 2016

Gary I use wood chips for mulch, so there is no rain bounce, and the grapes are protected under an eave up above. There is virtually no drip from above, they are sort of in a protected micro-zone. If I don't go with six cordons, would I potentially lose 33% of production? I only have six vines, so the stooping and crawling would be very minimal, not worth losing 33% of production. How close to the cordon are the fruit produced? I had insects (aphids) at the ten foot level. Thanks everyone for dialoguing at a very busy time of year.

TonyR · Sep 17, 2016

If you go with 6 cordons none of your fruit may ripen. But it is worth a try, and if it is to much you can always trim the vines different the next year. I would not trim the vines back, just clean them up in the spring.

Masbustelo · Sep 17, 2016

Tony that was what I was thinking, maybe try it and see what happens. Why do you think the fruit wouldn't ripen?

TonyR · Sep 17, 2016

If there is to much fruit it puts a strain on the vine. The same reason people cluster thin. Just more energy to go into remaining fruit.

Masbustelo · Sep 18, 2016

I remember reading an article that was saying that in a certain way vine spacing was immaterial. That you could plant 10 vines per 100 foot row, or one plant and that eventually both 100 foot rows would yeild the same. The downside being that if something happens to your one vine you are out of business. Also that it would take forever to fill in the 100 foot long trellis with one plant. That somewhere in California at a university there was a famous vine experiment like this. I can't locate the article. Can anyone guide me to it?