This has been one of the driest years I can remember. Right now in San Jose rainfall is at about 40% of a normal year. We’ve only had a couple of good storms go through. Mostly when we have had rain though it has been a light drizzle more than real rain. The winter months of December, January and February had almost no rain at all.
The natural question to ask is how will this effect the vines and potentially the grape harvest in 2012. The answer is – not very much. The vines are dormant in the winter so not using any water. Rain during that time is important to build up reserves for the dry summer months in the soil, but not important for the plants at that time.
I took the picture below on Wednesday of the Mourvedre vines in the front yard. They are just starting to wake up and grow. Now is when they need rain and water and right now we are getting regular little storms. It’s been more than enough for the vines right now. It has also been cool with highs in the low 60’s. That means the plants will be growing slowly and don’t need a bunch of water just yet. It also means there is no risk of mildew since mildew needs temps to be over 70 degrees.
Another good side effect we will see this year is that the lack of rain has kept growth down between the rows. You can see that in the picture below. At this time last year the cover crop was a foot tall. Those cover crops, and weeds compete with the vines for water, and this year those plants are small and won’t offer much competition. Last year we had to mow three times in most vineyards and some weeds grew to 5 feet high. This year we’ll likely mow just once or twice and it doesn’t look like anything will be over 18 inches tall.
We can’t count on the perfect timing of the rain though through the rest of the year and the amount of water in the soil is going to be an issue if we don’t get a lot of rain in April and May. That’s why we have drip systems though and we can turn them on if we need them. We usually don’t have them on so there will be some additional work we’ll have to do to get them ready before we can use them. This means turning them on and walking every row to see where they have gotten leaks since we lasted used them and fixing the leaks.
So we’re not really worried about the rain shortage or drought at all. Drought years like 2007 and 2009 have turned out to be some of the easiest farming years we’ve had, and produced great wines. If we have to turn on the drip systems we’ll have additional costs in water and maintenance. Those should be more than offset though in the savings from mowing and weed control. Look for an update on the rain situation in May. That’s when we will decide about turning on the drip systems or not.