Nearly two months have passed since I wrote about pruning. Here in the Rogue Valley we’ve spent much of that time waiting and worrying. It has been cold, and very wet, and our vines are off to a slow start. On May 6th we had a frosty night, with temperatures dipping several degrees below freezing and causing some damage to the tender, young shoots.

From an academic perspective, these are interesting times to evaluate the pros and cons of the two main pruning techniques, spur and cane. From a vineyard management perspective, however, it is downright annoying. The results of the frost will be felt throughout the growing season, requiring additional hand-work and a sharp eye to spot the shoots and clusters which, having formed from secondary buds when the primary one got frozen, will be ripening fruit (if at all) at a pace behind that of the majority of the vineyard. We will have to be vigilant early on about removing any fruit which threatens to be unripe at harvest time.

Upon inspection at Gold vineyard, the spur-pruned plants appeared to have done a little better in the cold, if only because at each spur position there were five or six green shoots, so there was some insurance against loss of the uppermost (albeit the most fruitful) ones. The vines with canes that were frosted, however, will likely have areas devoid of healthy shoots and will yield a reduced crop as a result.

Still, there are plenty of very healthy-looking shoots out there. These are Viognier from Gold vineyard:

This cane-pruned example shows how nicely this pruning method provides a well-spaced, uncluttered line of shoots, making the process of shoot thinning (removing excess shoots to prevent crowding) relatively fast and easy. This is, in my mind, one of the big advantages of cane pruning, compared to the relative clutter of growth at each spur.

Which would I rather shoot-thin? One can see that there is fairly little to do to the cane, while the thinning of just two spurs on a cordon required some careful work on this Sauvignon Blanc at Upper Five Vineyard.

Before shoot thinning:

…and after:

Terry Sullivan has chosen cordon pruning, with its orderly rows of short spurs, for his vineyard for the simple reason that he doesn’t like to cane prune. Regardless of his motivations, it seems a wise choice considering the vigor of his Sauvignon Blanc, and the wider spaces between vines to accommodate its growth habit. Cane pruning can be troublesome at spacing greater than six feet between vines, so the permanent cordon makes sense here.

Still, just like the pruning process itself, the resulting shoot-thinning process is more repetitive and simple with the spur, and more nuanced and subjective with the cane. When evenness and consistency are the goal, the spur is difficult to get wrong, and so is currently the preferred choice of most winegrowers in this region.

We would be wise to remember, however, that the first buds on every new shoot in 2010, whether it grows from a cane or a spur, are forming in unfavorably cool conditions, which will tend to restrict their fruitfulness in the following year. Spur-pruned vines in particular may shower fewer, smaller clusters in 2011 because of this cold spring. The good news is that this can sometimes mean less work thinning the crop down, and may even bode well for a low-yielding, high-quality vintage.

But first we’ll get through this one.