Your neighbor has established a top wire cordon spur system. Since he only has one vine he can let it take over more space and still be balanced. Since you have two vines you need to figure out how many buds you can leave per vine and still be balanced. By balanced I mean enough foliage to properly ripen your fruit, and not more–you can check this by recording pruning weights or by looking at the thickness of your canes from last year. In general, pencil thickness is ideal–if your canes are smaller you had too many buds, if thicker than too few.
Check out a couple videos and then feel free to ask follow up questions.
Just saw your summer post. Your grapes are against your wall. Can see basement windows so you probably have french drains/weeping tile along the footings of your foundation to avoid water infiltration into your house.
Grape roots seek water. They can send roots down 20 feet and further.
In dry spells they will absolutely infiltrate your drains, potentially blocking them.
This is photos of tree roots but grapes can do the same:
If you have to dig up and replace your french drains that can be thousands of $$.
I personally would not plant anything deep rooting near my house.
Excellent University videos, thank you.
I am unclear about how many of last year‘s shoots to leave up to create new cordons? Where the cut off point if you’re trying to get as many grapes as you can?
A related question is how much do you prune away? According to the formula he provides, if I did zero Pruning then I should grow zero grapes on the vine?
Additionally, How many leaves etc are required on each new shoot to ripen a bunch of grapes (or if I cut the flower stem in half to create a smaller bunch)?
I checked the vines yesterday, and most of them are larger than pencil thickness (bull canes?). I was considering leaving cordons up similar to the style the neighbor guy did, on both vines. This would create 8 cordons, have room for a bunch of little shoots, like maybe 1.5’ long max, crowded.
What I did last year worked fairly well, although the shoots were pretty random coming out of the trunk\Cordon, and a bit of a mess. They were also huge, which seemed to work well for making giant bunches of grapes.
Perhaps the best option is what I did last year, but leave a bunch of spurs, to allow better placed and more, shoot production. Should each spur only be allowed to have one shoot with fruit?
And just to clarify, the only reason to have a giant vine with lots of cordons is for spacing? There’s no advantage in having more wood? What dictates overall vine size and production then?
So a standard 6x8 spaced vine in an area with rainfall during the growing season would probably have two cordons. Since you only have two vines (much less competition) you could potentially give them four cordons a piece. For reference–Concord vines carry around 80 buds in that 6x8 spacing. You are not trying to get as many grapes as you can. You’re trying to get as many quality eating grapes as you can. Left to their own devices (no pruning), your vines would put out a ton of grapes that would be acidic and low sugar. Animals are not as picky as us.
The general rule of thumb is 10 leaves per cluster to ripen. Cutting the flower stem in half, especially if done near bloom, will not have a huge effect on yield but will change the shape of the cluster and the spacing of the berries. Table grape producers “tip” their clusters to elongate them. Your large clusters and thicker canes suggest you did not have enough buds per vine last year. Part of the point of cordon spur is to organize the growth. Your random growth last year may work for a couple years but my guess is you’ll end up wanting to cut out and restart when it becomes difficult to tell where one cane starts and the other begins.
I wouldn’t fruit thin (drop clusters) until you have a handle on how many clusters your vine can support. Your rain guard will help but in my humid growing environment, more wood leftover from the previous year often means more spores/disease potential. In a cane pruned system you eliminate 80-90% of growth from the previous year. In cordon spur you may be cutting out a similar percentage but only of the previous years growth. I record yield per vine and pruning weight–pruning weight is weight of previous years growth only. This gives me a ratio (Ravaz index) that helps determine if the vine is in balance.
In your case, I’d just use the pencil test. If you wanted to you could go through and count the number of canes you grew last year (maybe make a system where they must have more than 6-8 buds to be counted). Maybe shoot for 25% more this year. Grapevines are very forgiving, as long as they aren’t 20+ years old you can just restart them if you get frustrated.
That’s very helpful DC.
Btw, here’s last years harvest:
The covered area is about 12’x7’. The single trunk/cordon used last year was about 4’. I left some spurs, and I left most of the new shoots, and thinned to 1 bunch per shoot,. I harvested 36 large good sweet bunches in total between the 2 vines. That means I had about 36 shoots in total. I haven’t pruned or weighed yet. Looking at the vine now, all of the last year’s growth has much more than 8 buds, Dozens in some cases with the growth having expanded up to 15 feet. The covered areas were pretty full of foliage with a lot of foliage extending out into the rain.
If I have the lingo right, Im thinking of a single cordon spur or cane pruning system. Basically what I did last year, but keep as many spurs or canes as I can on the Cordon. lots of room for expansion, but I may not have enough new shoots. Unless I can place say 2 bunches per shoot?
If I create new cordon’s this year, there’s not that much room, unless the new shoots stay much smaller than they did last year. Placement of the new thickest vigorous cordons May be difficult to get symmetrical. If I increase shoots numbers , will their size shrink?
The canes or spurs should be pencil thick. The cordons (or arms) support your canes, physically and by being the energy delivery mechanisms (similar to scaffold branches on fruit trees). Traditionally, pencil thick signified that the vine was in balance.
Ah, I meant to say cane/spur. So other than as a balance symbol, Is there a reason to only use pencil thick ones and prune off thicker canes/spurs?
And the only practical reason to use more cordons is if you want a larger vine (more fruit) or for spacing and better shoot selection?
You don’t have to only keep pencil thick, that’s just what you want to see next year. You’ll almost definitely have to keep thicker and maybe thinner cuttings to get to your bud number at which you think the vine will be balanced. I’m kind of overcomplicating it at this point.
More cordons is mostly for spacing and shoot selection but should give you more, and possibly better, fruit as a bonus.
Just to clarify, will adding more buds this year cause all the shoots to be smaller, or is each shoot growth likely to be just as wild as it was last year? I’m trying to select cordon location now and if I will be forced to put some shoots out in the rain.
Also, As long as a minimum of 10 leaves is left for each grape bunch, is it possible to put more than one bunch on the same shoot?
Additionally, what is the optimum time to prune? I imagine waiting until all the leaves have fallen off is best as it will allow the vine to optimize starch storage in the roots? And anytime before bud break in spring?
Thanks again DC!
dude, my foolish apartment manager, after the bad “pruning” of the flower plums killed the trees, had something like Alder fast growing planted really close to the building. It now is a trunk about 3 feet wide and the roots HAVE to be under the building by now.
I do not know how to tell them to pull these monsters out before it destroys the foundations.
This is true! I experimented with Concord and another grape by not doing any pruning, or very little, in 2018/early 2019 and got lots of not tasty grapes.
For this year I did opposite. In fall I did more pruning than ever before. I will see if I get any grapes, how many, and size and taste in fall.
The prior year I did some pruning and it was great, by the way. They tasted great. So I would suggest pruning.
Things are looking very good very vigorous. When thinning the shoots, I should get rid of the smaller weaker ones, and fruitless ones ? Also some have grown so vigorously the tops snapped off hitting the roof, should these be also removed? Wondering how much crowding I can get away with…
A bunch of roof hitters have snapped off like this, at less than a foot, few leaves, and grape clusters. Should they be removed, or will they continue to produce leaves elsewhere?
If just the tip broke off then the shoot will send out laterals (replacement shoot tips), usually from the highest axil (crotch between leaf and stem). Those laterals are even capable of forming clusters of their own (but will rarely ripen them). If/when you cluster thin those shoots whose tip broke off are good candidates–they’re likely to ripen their clusters a little more slowly.
