What to do about new growth on a grape vine
Hi grape growing friends,
I received this email from John and Randi, so I decided to reply to their email on my blog so everybody can have a look at it.
Here’s the email:
What to do about the new growth? I think about 20 bunches/plant is recommended, under the best circumstances, either red or white varieties. Do I pinch back the new growth at the mature stem, pinch back below the lowest bunch (I assume the plant needs leaves to produce nutrients for the grapes), let the new growth continue – removing only the bunch buds: how to balance roots with fruits?
OK here we go …
Although John and Randi didn’t mention the age of their grape vines in the email, I assume it is mature vines. New growth on a grape vine is easily managed by starting to remove water shoots.
Water shoots (as I call them) are shoots that develop from the old parts (arms and stems) of the grape vine – older than 2 years. These shoots normally do not produce grapes and only compact the vine and prevent proper sunlight penetration and air flow. Although water shoots can be used to renew a cordon (arm) when a cordon dies or become unfruitful, they are normally useless on a grape vine and should be removed.
Determining the crop size you want on your grape vines beforehand, is important and you should experiment with your own vines to see what the best load for optimum quality is.
Depending on how strong your grape vines are and off course the trellis system you use, 20 bunches per vine (like in the email from John and Randy) is okay, but with a well developed grape vine structure, good exposure to sunlight, correct bunch sizes and proper canopy management during summer, I succeeded in ripening up to 32 bunches per vine.
Some “grape growers/consultants” might tell you that this kind of crop sizes will result in lower quality grapes. Yes, that is true IF you do not look after your vine. I successfully prepare and pack grapes crops of this size year after year.
Now you might think: “What a windbag this guy is?” No, actually I’m no windbag, in fact I’m a rather quiet guy!
I’m telling you this because it is possible to grow grapes that produce that kind crop sizes. By removing all unnecessary shoots on the grape vine before flowering and even by reducing the number of flower-clusters at that stage, will unbelievably improve the quality of your grapes.
Like I said, decide on the crop size and count the number of bunches before flowering starts. Here is the formula I normally use.
Say for instance I decide on a crop size of 30 bunches per vine, I then ad 60% to that number
30 bunches + 60% = 48 bunches per vine (the rest will be removed after fruitset, when you will be able to choose the 30 best bunches from the total)
If I have say 70 bunches on the vine at that stage (which is possible!), I will remove 22 of those bunches. I start by removing inferior shoot, even if they have bunches on them. I remove all double shoot that developed from the same bud (remember that a bud on a grape vine is actually 3 buds combined) and then I remove individual clusters from shoot that produced more than one cluster per shoot.
KEEP ON COUNTING THE GRAPE CLUSTERS AS YOU PROCEED!
Once I’ve reached 48 clusters, the grape vine is now ready to go into flowering.
You see my friend …
By removing unnecessary clusters before flowering, the vine is under much less stress – when the clusters start flowering, the grape vine is under an enormous amount of stress.
I never remove leaves at that stage. Rather leave the grape vine until after fruit set and then remove leaves. If you feel that some of the shoots is growing out of control, you can set them back by removing the growing point of those shoots.
I tried to explain this in simple terms, so I hope this will help you grow your grape vine the correct way.
Good luck and if you have any questions, just add a comment below this post.
Take care
Danie
The Grape Guy
Tagged with: how to grow grapes
Filed under: growing grapes • how to grow grapes
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i have just found this site. I must say what a great site i like the way that we can post a questio and you respond with your answer, great name and great site well done
Hi,
I have grown some cuttings from an old vine (that produced fruit) in the UK.
The plants are now about 3 years old and appear healthy with lots of foliage but have never flowered.
Any tips on how to get these vines to fruit?
Many thanks,
Martin
Hi Danie,
I planted my first grapevine this year in my backyard. It’s a Vanessa seedless table grape. About 2 weeks after planting, the vine started growing at the rate of about 1 1/4 inches per day.
2 weeks ago, it surpassed the height of the 4 foot stake that I was training it up. I extended the height of the stake by attaching a thin piece of bamboo to the top of the stake but while I was doing this, the vine fell over and the growing end touched the ground.
Since that day, the vine has only grown about 1/2 inch over 14 days and the growing end looks dead. The leaves closest to the ground are also starting to rot and curl. The leaves turn yellow at the edges first and the yellow eventually spreads to the center.
It’s possible that ’round up’ was carefully applied to the area that the growing tip fell on when it hit the ground but if so, it would have been applied more than 30 days (and 20 rainfalls) prior.
Is there anything I can do to save this vine or will I need to start over from scratch next year?
Hi Jim,
I doubt if it is the Roundup that causing the symptoms. Normally, after about 7 days, Roundup that was sprayed on the ground or soil, will have no effect on green parts of any plant.
OK, with that out of the way;
First Jim, where are you from? I’m asking this, because it can be that it is the end of summer and that the grape vine is steadily going dormant. The yellowing of leaves from the bottom, is normally a sign of upcoming dormancy.
The fact that your grape vine isn’t growing as vigorous as before, can also be a sign of dormancy.
Do you have pictures of the vine? It will most certainly help.
Hi Danie.I read with interest your system of pre flowering bunch removal and that all sounds sensible and I will be more vigilent to remove excess early. I noted you said leaf removal should not happen pre flowering. The last 2 years I have removed quit6e a few leaves around any clusters right on start of flowering. My reason for this was that my sprayer is not fan assisted so really needed clear access to get those pre bunch closure sprays into the bunch as we are in a potentially high humidity area and botritus can be quite an issue. Hasn’t seemed to create a problem with rippening or anything. What do you think removing those leaves may have detrimental effects on fruit set? Many Thanks Phil
Hi Phil,
You have a point there, but the reason I do not remove grapes prior to flowering, is as you said; it will effect fruit set. If you grow grapes for making wine, this will not be a problem, but if you grow grapes for eating and export, like I do, you don’t want too compact grape bunches. Removing leaves can result in the vines not aborting enough berries and will stick to buches – these berries then have to be removed by hand (expensive and time consuming process).
Hi I have some white grapes that have split. They are in my greenhouse in Alsager Stoke-on-Trent England. I’m not sure why they are spliting could it be disease or under watering. Any advice welcome. The grapes are about half an inch in diameter and should be ready to eat in about 1 months time
Hi Nigel,
It could be because of a fungus disease (powdery milldew for example), or high humidity inside the green house.
Do you use mist irrigation in the green house?
Dear Grape guy,
My name is Jessica and you seem to know a lot about grapes so thought I’d post you a very rookie question. We have a beautiful south-facing slope, large flat area, but is the drain field for our septic system. We were wondering if we could start a mini-vineyard here but are concerned the root system of the grapes would be too deep and would interfere with the drainfield. Do you have any knowledge of this? Any comments would be greatly appreciated! Sincerely, Jessica Yoos (jjyoos@yahoo.com)
Hi Jessica,
The roots of the grape vine can penetrate the soil very deep, especially to look for water. I don’t think planting a grape vine on a drain field would be such a good idea, as the vines will for sure go after the “water” that runs in the drain field.
We have just moved into the Nigara area and we have a grape vine on our arbour. How do I know what kind of grapes we have.We have had Blue grapes at another location so we are fimiliar with those. Looking forward to your advice.
lucillehubley@amtelecom.net
Hi,
There are about 20 000 different varieties world wide, so telling what you have is not easy.
The study of grape varieties is Ampelography. You can do a google search to read more about that.
Hi grape guy
please how cane i make abalance between number of bunches and hrvest time
Hi
It all depends on how old your vines are and what trellis system you use. Shoot diameter also determine if you will give the shoot a bunch or not.
On a gable trellis system with a planting distance of 3 meter (row) by 2 meter (between vines) I leave about 25 to 28 bunches per vine.