How to Shoot Thin in the Vineyard

[acorad]

How to Shoot Thin in the Vineyard!

I hope this is helpful.

 

[Cynewulf]

I was hoping you’d do one on shoot thinning - super helpful as always! It appears that frost may be doing my shoot thinning for me this year, but this will be helpful when the figurative dust settles and I know what the remaining growth looks like over the next couple of weeks. Thanks again for doing these.

 

[acorad]

I was hoping you’d do one on shoot thinning - super helpful as always! It appears that frost may be doing my shoot thinning for me this year, but this will be helpful when the figurative dust settles and I know what the remaining growth looks like over the next couple of weeks. Thanks again for doing these.

Happy to do the videos Cynewolf, thank you for letting me know they've been helpful!

 

[treesaver]

Thanks for posting that, good info for sure!

 

[acorad]

Thanks treesaver!

 

[BarrelMonkey]

Interesting and helpful, thanks. I don't grow wine grapes but I have a few table grape vines in my garden (Black Monukka) - also a 'Princess' which I just planted this season. I am using cane pruning rather than spurs and have been pruning back to 1 shoot per node; does this make sense or would you leave 2 as for spur pruning? (And, I guess, would you approach table grape pruning differently in general?)

 

[acorad]

Hi BarrelMonkey, I'm not really familiar with your varietals or your local growing conditions, but I would guess that you need roughly 5 - 6 feet of shoot to ripen the grapes on that shoot? So I would try to balance the number of shoots on each vine such that the fruit gets ripe and you don't have shoots that are way too short or way too long. Kind of trial and error over a couple years to get an idea of how many shoots you should let grow on each vine.

 

[BarrelMonkey]

...but I would guess that you need roughly 5 - 6 feet of shoot to ripen the grapes on that shoot? So I would try to balance the number of shoots on each vine such that the fruit gets ripe and you don't have shoots that are way too short or way too long. Kind of trial and error over a couple years to get an idea of how many shoots you should let grow on each vine.

That's a good plan... last year one of my vines produced lots of good fruit whereas the other was disappointing. It's hard to directly compare since they're in different locations, but the poor producer did have a lot more nodes and shoots which I should probably have thinned. This will only be my second season so hoping to learn from it as you say.

Unfortunately most of my harvest last year was taken by a hungry raccoon, so that's a separate problem I have to solve!

 

[treesaver]

BM, a cage trap is your friend with a marrading ****. Make sure you don't make your problem someone elses after you catch him. Trash pandas are everywhere, and once they key on your grapes, they won't quit till they eat them all.

 

[acorad]

I also had raccoon problems in the past, so I strung up a couple lines of electric fence. No problems now for years!

 

[Handy Andy]

After shoot thinning at what length do people cut the tips of vines??

I have some vines more vigorous than others, that might get damaged by wind.

Hi BarrelMonkey, I'm not really familiar with your varietals or your local growing conditions, but I would guess that you need roughly 5 - 6 feet of shoot to ripen the grapes on that shoot? So I would try to balance the number of shoots on each vine such that the fruit gets ripe and you don't have shoots that are way too short or way too long. Kind of trial and error over a couple years to get an idea of how many shoots you should let grow on each vine.

How many leaves and clusters would you expect to have in a 5-6 foot long shoot??

 

[balatonwine]

The "rule" is rather simple.

On canes, one shoot every 10 cm on a cane. That is simple and easy to do. I posted about this 8 years ago:

https://stcoemgen.com/2013/05/11/thinning-buds/
On cordons, two shoots on every stub. Stubs should be every 20 cm.

All else is removed. Except..... with cordons it is a good idea to sometimes leave a third shoot (but remove its clusters) even if weak but close to the cordon to prevent long stubs over time. Thus with cordons it can be more complicated.

 

[Handy Andy]

On cordons, two shoots on every stub. Stubs should be every 20 cm.

All else is removed. Except..... with cordons it is a good idea to sometimes leave a third shoot (but remove its clusters) even if weak but close to the cordon to prevent long stubs over time. Thus with cordons it can be more complicated.

How many clusters should I leave on a shoot assuming it has more than one cluster?

I think you answered these questions already
Should shoots with no clusters be removed or left in tact? If they are closest to the cordon would it be a good idea to cut them back to a couple of leaves to allow more light into the shoots with clusters?

 

[balatonwine]

How many clusters should I leave on a shoot assuming it has more than one cluster?

I think you answered these questions already
Should shoots with no clusters be removed or left in tact? If they are closest to the cordon would it be a good idea to cut them back to a couple of leaves to allow more light into the shoots with clusters?

These are very simple questions, and good questions, but ones with extraordinary complicated answers. Give me a little time to think out the best way to reply in a short manner, and I will reply soon.

 

[Obbnw]

These are very simple questions, and good questions, but ones with extraordinary complicated answers. Give me a little time to think out the best way to reply in a short manner, and I will reply soon.

I'm still waiting ; ) just teasing I just looked through this thread today as I am pondering how much "shoot thinning or cluster removal" I should do or if I should I just let them go.

This is year 5 for me.
In year 2 I let most of the vines produce. The wine was excellent and quantity was much more than I expected.
Year 3, season started cold and ended cold, averaged 20 brix when I had to pick due to the earliest hard freeze since I lived here (25 years). Wine sucked.
Year 4, severely thinned some vines, let others go. Saw no correlation between thinned and let go for ripening or quality (fresh grape taste from someone whose sense of taste is not great - so my perception of quality is questionable). Wine seems OK but not as good as year 2.

Year 5, this year. Let them all go wild, they are doing great but the number of potential clusters seems huge. I was going to let them go all year but am second guessing that decision.

Spent some time reviewing various literature and it seems like the reduced yield equals better quality may be more than half myth.



Climate here is hot and sunny, elevation is 4600ft, vines are 10' tall and spaced at 4'.

I'll let them go for another 3- 4 weeks, Stuff I read implied it is better to cluster thin after fruit set but before veraison.

I'm still leaning towards letting them go for the most part (there are a few 5 clusters per shoot and some of the buried clusters that I may pull out).

Not really looking for advice as much as comments on your experience with overcropping/undercropping etc. although I will certainly consider any advice.

Local 10 day forecast for reference (I suspect the 102 is in the record setting range).

 

[Snafflebit]

Year 5, this year. Let them all go wild, they are doing great but the number of potential clusters seems huge. I was going to let them go all year but am second guessing that decision.

Spent some time reviewing various literature and it seems like the reduced yield equals better quality may be more than half myth.

I think dropping clusters just to reduce the yield of the vine will not necessarily improve the quality of the wine. Most cluster thinning is done to cull the grape clusters that would not ripen by harvest. Lower yield is more of a side effect of the process

 

[Handy Andy]

I adopted some mildly neglected vineyards last year, with no prior vine growing experience, so am still learning. The vineyards had variously 2, 3, and 4 wires in them + a couple of trellises. It dawned on my power intellect this year that a third wire was required. This has allowed me to open up the vines a little and seperate the shoots from adjacent vines, as some were getting over crowded not allowing light into the canopies. Simple math > shoots with fruit need according to what ive read at least 12 leaves to ripen clusters > leaf spacing 3 to 4 inches and healthy shoots, means the shoots are going to be 36 to 48 inches long above the bottom wire. So I added a 3rd wire to all the two wire systems, increasing their height to a about 5'6 ish. 1.6 ish metres.

I opted to thin shoots, with no grape clusters, back to 4 leaves with a view to improving the shapes of my vines next year.

Anything looking sick, has been removed. Some of my cordons were damaged and on post mortem with a secateur, showed the cordons appeared to have some form of rot to the core in places, possibly due to the various mildews I adopted last year with my vineyards.

All is good in my vineyards at the moment, but unlike sky diving, if it goes wrong (so much for skydiving) I should get another chance next year.

 

[Obbnw]

Last year I didn't see an acceleration in ripening for the vines with fewer grapes. I do have one vine that has been a high producer but is always 2 weeks behind most of the others (microclimate/exposure) - maybe I'll thin that one and see if it can catch up.

I have seen both "leaves per shoot" recommendations and total leaf area per production recommendations and have wondered if the leaf area has to be on the same shoot or is more effective on the same shoot or if it doesn't matter as long as the plant has x sf of leaf area per lb of grapes.

 

[Snafflebit]

I am sure that leaf area is what is important, but it would be too hard to calculate. So, a fixed number of functional leaves is a good rule of thumb.

 

[Obbnw]

Well the heat cluster thinned for me, the early blooms set fruit really well but half the later ones shattered in the heat.

So far it looks like a good year. Curious what the summer heat is going to do. So far June has been record setting hot and the forecast just shows it getting hotter.

I noticed the Malbec didn't shatter as much as the Tempranillo. The Malbec are up against a 7' concrete wall retaining 3' to 5'. I think the wall must temper the heat.

I've got high hopes for this year.