Lots of Leaves and Vines/ Few Grapes

Here's a question regarding my vast (3 vines) vineyard of 3-yr. old Steuben vines. They were trimmed back properly last winter and have grown quite well. Too well perhaps, because I have lots and lots of leaves and vines but virtually no grapes. When I look at the vineyards of commercial wineries, I notice that the vines are fairly compact. Mine are sprawling all over the place. Do they need pruning back? All I've read says to prune before the new growing season, not during it.

Dan,

It's a good idea to prune during the growing season too, especially when there is a lot of rain. Too much vigor gets you lots of leaf and wood.

As for the low fruit--maybe you had a bad bud break; a frost that zapped them or something like that. How old are the vines?

I have never grown a grapes Dan, but I suspect that the wet cool spring was more benificial to vine/plant than it was for the fruit. I have two (only two) tomatoe plants and they look great. The do have tomatoes on them, maybe 15 or so ranging from very small to tennis ball size, and I will enjoy them when they ripen. But I think I should have suckered them during the big growth spurt they had in June to reduce the canopy some, and let the plant put it's energy into production of fruit.

Hi Dan - I looked in my literature and checked out a few web sites for canopy management, but didn't turn up anything. However, excessive growth of vines is pruned during the growing season. In fact, I've seen machines, attached to tractors, that remove all leaves and canes that stick out of the sides and top and the trellis. Kind of like large hedge clippers. Being only 3 years old, they may be just too young to be bearing fruit.

Thanks for checking Howie. It's surprising how the books and brochures go into such great detail about pruning back after the season but say so little about what to do during the growing season.
By the way, I lost a vine a month ago in an interesting way. It had been doing fine, then I noticed lots of growth coming up from the roots. Next the leaves on top began to fall off and the wood shriveled up. In a week or so the only growth was from below ground. I described it to my son-in-law. He said it was a clear case of the graft having failed and that the growth I now was seeing was the root stock. I don't imagine it makes into much of a wine.

Oops! I missed the 3 year-old note. Yes, they likely are too young, and should have had the fruit pruned away the preceding two years, to strengthen the vines.

The 4th year should be better at fruit production, provided you prune properly in November/Dec--recommend you leave no more than ten buds on 2 or 3 canes.

Thanks for checking Howie. It's surprising how the books and brochures go into such great detail about pruning back after the season but say so little about what to do during the growing season.
By the way, I lost a vine a month ago in an interesting way. It had been doing fine, then I noticed lots of growth coming up from the roots. Next the leaves on top began to fall off and the wood shriveled up. In a week or so the only growth was from below ground. I described it to my son-in-law. He said it was a clear case of the graft having failed and that the growth I now was seeing was the root stock. I don't imagine it makes into much of a wine.

Depends on the rootstock...

He said it was a clear case of the graft having failed and that the growth I now was seeing was the root stock. I don't imagine it makes into much of a wine.

All the vines I planted in the past two years are own-rooted - no grafted rootstock. About 25 years ago, I unsuccessfully planted a vineyard (did everything wrong), but a friend (who has since moved away) gave me cuttings of a vine that was supposed to be an experimental rootstock, but if allowed to grow and bear fruit would yield seedless grapes. They didn't last very long, as I recall.

Dan, first of all I need to ask what pruning strategy did you use: pruning to long canes or 2-3 bud spurs? Your scenario sounds exactly like what happened to my Concord vine last year. The growth of canes and leaves was rampant all summer, but the vine only produced 3 bunches of grapes. This past winter I pruned it to two long canes with about 14 buds each, and this year I have over 40 bunches of grapes on that one 3-year-old vine that I started from a cutting. Labrusca likes to be pruned to long canes; this is how it is most productive. I once read that labrusca puts most of its flowers out towards the "ends" (or extremities) of its growth because it "thinks" that's where the sunlight is going to be. Kind of an evolutionary response to growing in the woods among trees, I suppose.

I agree with Paul. I think 10 buds on 3 canes or 15 buds on 2 canes is fine.

I think 10 buds on 3 canes or 15 buds on 2 canes is fine

Each vine was 2 canes, and I'd say the cut back probably resulted in less than 15 buds on the 2 canes.

Dan, I just realized that I never really explained why labrusca ought to be pruned to long canes. The reason is that labruscas are high-vigor vines, and if they are pruned back too harshly each year what happens is that (1) the vine puts its vigor into making long canes, but (2) those canes tend to be unfruitful, because the vine is most fertile towards the ends of the previous year's growth - again, that evolutionary adaptation to growing in the woods and needing to reach sunlight.

It took me a while to understand my beloved vines! This year, the Concord just outdid itself with fruit.

Thanks Paul. Next time you prune perhaps you could post some before and after pictures.

Thanks Paul. Next time you prune perhaps you could post some before and after pictures.

Dan, I'd be happy to, although I think that this diagram shows it extremely well. It's a before- and after-pruning snapshot of what the vine ought to look like:

<table border="0" align="center" valign="top"><tr><td><img src="http://muextension.missouri.edu/explore/images/g06090art08.jpg" border="0" align="left"></td></tr></table>
Now, this picture is really good for labrusca vines because labruscas do tend to grow into something resembling a really bad hairdo. It's the vinifera vines that tend to grow upright, and they do best with traditional cordon/spur pruning (though I've read that Nebbiolo, interestingly, should be cane pruned!).

Shown in the picture but not explicitly marked as such are the renewal spurs - one single-bud spur for each 10-15-bud cane that should be left while pruning. The spur is always located near the trunk; its purpose is to produce the next year's fruiting cane while the current year's long canes produce flowers and then fruit. The spurs will send out long canes because they tap into the vine's vigor. The renewal canes will typically not be fruitful while they are being formed; they will, however, be fruitful the following year.

Hi Dan,
From what I have read, the first 1 to 3 years of a young vine’s life should be dedicated to training it on the trellis system one choices to grow it. If this means sacrificing the “small” fruit clusters, so be it. If one has decided to go with a single trunk or multiple trunks, this is the time to train the vine. Patience rules here and in the long run will hopefully “pay-off”. (I agree with Thomas P, maybe the snap of cold weather experienced in upstate NY affected the flowering and fruit development of your 3 year old vines). The whole idea behind pruning is to simplify the “growing area”, and keeping it “orderly” (maximum sun, good air circulation and ease harvesting). When pruning especially on the east coast always think of a “back-up” or “insurance policy” (maybe leave a spur (short fruiting cane) for every fruiting cane you leave on- cane and spur renewal system), and after the vine grows older and the “growing area” becomes more chaotic, don’t just nick off those basal buds that can be used to “renew” or “re-establish” order to the “growing area”.

Salute