Spring weather

By Jeff Miller 2011-3-29 15:10:05

I’ve always been a big believer that the weather during the ripening period (roughly August 1 until harvest) was a critical factor in the quality of the grapes and resulting wines. Grapes that ripen under a lot of heat reflect that fact, and you end up with wines having pruney/raisiny characteristics.

But what about the weather earlier in the year? Like, for example, now. As I’m writing this, the weather is slightly overcast. It’s been sunny for short periods, but, by and large, the last week has been marked by rain. Persistent, and at times heavy, rain.

It’s a general rule that the weather early in the season has a lot to do with the size of the crop. Lots of sun encourages the development of buds and canes. More buds and more robust buds and canes, the more robust the grape clusters. So the more sun earlier in the season, the more grapes at the end.

It’s also a general rule that the weather this spring impacts the yield the following year. That’s because the buds that will result in next year’s crop are laid down this year. The more robust those buds, the more robust will be the canes that grow out of them next year.

So this year, at least barring some pretty sunny weather over the next several weeks, has all the earmarks of a low yield harvest.

The problem with this view, though, is that much the same thing could have been said about last year. Last spring was pretty dismal, as was the spring before that. Both should have pointed to a low yielding harvest. Not only that, but last year we got some heat waves later in the year that created a lot of shrivel, and resulting crop loss.

So, between the cool springs and heat waves, we should have had a harvest that was way down. In fact, that’s what everyone was predicting. And most people I know experienced a substantial shortfall in their yields compared to a year earlier.

But when the final harvest report came out, it turned out that the overall tonnage was off by a tiny amount from the year before. What should have been a major effect turned out to be a minor one, almost a miniscule one.

So what gives? I really don’t know. Certainly our vineyards’ yields were, as we expected, way down, but apparently most of the state did quite a bit better than did our Suisun Valley. It certainly casts a lot of doubt, at least in my mind, on the idea that cool wet springs have all that much to do with the size of the harvest, either this year’s or next’s.

One thing that is welcome is a good amount of rain in the winter. I don’t think it has that much to do with the amount of water in the soil. After all, the soil can hold only so much water, and any excess over that amount drains off. Since in all but the driest of years, there’s enough rain to fill the soil to capacity (with hillsides, which experience a lot of runoff, being a possible exception), the amount of rain isn’t all that relevant for this purpose.

But the water that drains from the soil does serve a useful purpose, in that it removes the salts that can accumulate in the soil, particularly in an irrigated field. Since these salts, in high concentrations, can have a toxic effect on the vines, having a lot of water going through and draining out of the soil, taking the salts with them, is a benefit.

So, in the end, I can’t say I have the same belief that the weather in the early growing season is nearly as important as the weather during the ripening season. At least, nothing in the last few years has convinced me otherwise.

From Artisan Family of Wines