Thursday, June 10, 2010

Pruning grapes

It’s tough to answer a question from homeowners on how to prune the American grapes we grow in this area. The first roadblock is their mental picture of California grape vineyards with spur-pruned grapes trained to a head or cordon. This isn’t the way American grapes should be pruned.

American grapes don’t produce fruit next to the main trunk. Instead of European wine grape-style pruning to 2 or 3 buds, we leave 6 to 18 buds because of the vigorous American vines. The more vigorous the variety such as ‘Concord’, the more buds can be left.

The second dilemma in answering the how to prune question is that vines are usually already sprawled over an arbor or pergola. Making any sense out of vine structure and counting buds isn’t realistic at this point. I advise the “clear dead canes out and prune live canes to keep the vine on the arbor approach.”

With the vigor of these American vines, pruning wrong is awfully hard to do because rank growth will take care of any pruning “mistakes” if there is such a thing. The real mistake is not doing any annual pruning at all. In some form this usually meets the two real viticultural pruning objectives of shaping vines to meet gardener’s needs and balancing fruit production with vegetative growth.

The vines shown in the photo top left contained dead canes from the previous season. They were recently pruned to remove dead wood and clear the way for this season’s growth (obviously well along). Two varieties are grown on this arbor, ‘Concord’ and ‘Himrod’. The two “after” photos right show the arbor after pruning and the amount of dead wood cleared out.

What are your thoughts about how to prune and the harvest results you’ve gotten with your method? Please tell us where you live and what grape variety you’re growing.

Photo credit: All 3 photos Carl Wilson.

1 comment:

  1. I have been growing Einset grapes in Greeley, CO for approximately 7 years. I prune in February down to one or two buds per major limb. I noticed water/sap dripping at spring cuts and reduced productivity. So I switched to dormant winter pruning. The more buds I leave...the smaller the grapes but more quantity. Einset grapes are a sweet dinner grape adapted to colder climates because they set later in spring.