A pruning masterclass: cane-pruning Sauvignon in Marlborough

The Awatere: time to prune

This morning Mike Eaton kindly took me out to a vineyard he’s working with in the Awatere Valley (Marlborough, New Zealand) to give a quick pruning masterclass.

Here’s the film – it’s quite long at 14 minutes, but it goes into detail about some of the decision-making process in pruning a vineyard.

In Marlborough, all the Sauvignon Blanc is cane pruned. When you consider that Sauvignon makes up 80% of the 25 000 hectares of vines in the region, that’s a lot of work. And finding labour is getting to be quite an issue. While harvest is now done by machine, you can’t get a machine to cane prune vines (although for spur pruning a machine can do most of the work, which is then tidied up by hand).

What is cane pruning? A cane is a shoot from the previous year, and the idea is to leave 2, 3 or 4 of these from the mass of canes left from last season’s growth. These are then tied down onto the fruiting wire(s), and each bud will produce a shoot, hopefully with a bunch or two of grapes on it. As well as leaving canes, good pruning leaves a couple of replacement spurs which will then bear the shoots in the right position for them to be next year’s canes.

Why cane pruning? It’s more complicated than spur pruning, which involves having two permanent arms (cordons) on each side of the vine trunk, from which a short spur of two or three buds is left at each node. But some varieties – notably Sauvignon – have low basal bud fruitfulness and don’t work well with spur pruning. Pinot doesn’t have this low basal bud fruitfulness, but spur pruning isn’t so good for it either because the first couple of buds typically produce low quality bunches, with uneven ripeness between them. So this is usually cane pruned in Marlborough, too.

A young vine pruned to two spurs and two canes

Some pruning tips:

  • You want the vine head height to be about a secateur’s length below the fruiting wire. Pruning choices that keep the head in the right place allow the canes to be tied down onto the fruiting wire nicely. But as the trunk grows the head rises a bit, so by the time the vine is ‘adult’ it will be a little higher. This is worth thinking about when choosing replacement spurs.
  • For young vines, aim to leave two spurs and two canes. This is Marlborough, so a lot of Sauvignon here will be three or four cane.
  • In the second year, it is sometimes OK to leave short spurs on last year’s cane in the absence of a suitable cane. This also helps keep the vine attached firmly to the wire.
  • In choosing canes, try to keep the head zone clear. And try to respect the sap flow of the vine by taking the canes and spurs from the outside, rather than coming back towards the head.
  • If you choose a spur above the cane, the spur won’t get the right sap flow, which will all go to the cane. The spur is only of use if it grows well the next year.
  • Ideally, take the canes from two-year-old wood.
  • Do any major cuts as early in the life of the vine as possible.
  • The first choice, especially in a young vine, should be the spurs. Choose well, and pruning will be a lot easier the next year.

 

Leave a Reply

 

 

 

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

*