A rainy (and not-frosty) March gives hope for the 2014 growing season

As the last raindrops fall from today's minor weather system and we turn toward a warmer forecast for next week, it seems like a good time to assess this spring's conditions so far, and start to look forward to its impact on the 2014 vintage. Today's sprinkles were the last of four rainy days this week that together dropped about an inch and a half of rain at Tablas Creek. Our rainfall total for the winter has grown to nearly 10 inches, still a far cry from our norm of 25+ but so much better than the 2.5 inches we'd accumulated by late February.  When the sun comes out, it really does feel like spring.

The vineyard is electric green, making up for lost time thanks to the newfound moisture in the soil.  These two photos, both taken from the top of our oldest Grenache block, will give you a sense of how the landscape has changed in the last month.  First, from Wednesday:

Next, from exactly a month earlier (March 2nd) just after our first big rain of the winter:

It's not just the cover crop that's growing; as you can see from the top photo the vines are well along too.  As was clear in mid-March -- when we noted that budbreak was beginning at least two weeks early -- the vineyard has decided that spring is here and it's time to get moving.  Grapes like Grenache (mentioned earlier) and Viognier (below) are furthest along but even the late-budding Roussanne and Mourvedre are past the point where they could withstand a serious freeze.

As for frosts, so far we've dodged successfully.  The last few nights were chilly (down into the mid-30's) but despite the cold air mass aloft, the nights stayed just cloudy enough to keep temperatures above freezing.  We're expecting one more cold -- but probably not frosty -- night tonight, and then a warming trend is supposed to push temperatures into the mid-80's by the middle of next week.  Each night that we avoid a frost is meaningful; if we have, for example, a 5% chance of a nightly freeze on March 15th, decreasing steadily to near zero on May 15th, every two weeks that we avoid a frost roughly doubles our chances of making it out unscathed. The math involved carries some oversimplistic assumptions (chiefly that each night is an independent variable, unconnected with the nights around them, which is clearly untrue) but it's still illustrative, and shows the chance of avoiding a frost every night for 60 nights at just 20%.  If we have to avoid just 45 nights, our chance of escaping rises to 39%, while if we have to avoid just 30 nights it rises to 64%, and at 15 nights it's all the way up to 88%.  This shows the enormous benefits of avoiding frost in the first 15 nights of budbreak, which should be intuitive: each day later in the year brings more daylight hours, shorter nights, a more northerly jet stream, greater heat accumulation and a correspondingly lower chance of a nightly freeze.

The net result, if I've lost you in the technical paragraph above, is that we're exceptionally grateful to have avoided a frost for the last three weeks.  We're a long way from out of the woods, and I'd still estimate our chances of escaping entirely at less than 50/50, but it's looking less desperate than it did three weeks ago.

In the vineyard, the late rain means that we're behind on getting the cover crop under control.  Until recent days, there wasn't a cover crop to speak of, and we're happy to see it finally growing, but it does mean that we'll be weeding later into the year than we're used to, and that the late moisture makes it more likely that we'll need to make multiple passes through some blocks.  For example, the block containing the head-trained Mourvedre vine pictured below, which was spaded before this week's rain, will certainly need to be re-weeded:

Unfortunately, our sheep, alpacas, llama and donkeys will be less use than normal in our weeding efforts this year.  The late rain meant that there wasn't much for them to browse until recently, and since our animal herd will happily eat the new shoots off the vines, the early budbreak will soon force us to move them to unplanted sections of the property. Their impact there will still be beneficial, but even in a normal year there exists a six-month stretch where they're exiled from the producing vineyard, so extending that term by additional months is unfortunate.

Still, we're very happy to see the vineyard looking as good as it is, given the conditions it faced this winter.  And it is looking very good.  The vines look healthy and even, the vigor seems surprisingly good given that last year was dry and this winter even moreso, and it's clear that our care in reducing crop levels preemptively last year has had positive benefits in the vines' health this year.  The last month has been just what the doctor ordered: wet and not frosty.  If we see the same thing in April, we'll have cause to feel fortunate indeed.