Out of a deep sleep

The Winter is over, and Spring is here. It seems that when the weather begins to improve, I see more people out and about. The long cold winter is over, and we are all coming out of our winter slumber, and ready to move forward into the warmth of summer.

The same is true in the vineyard. Grapevines go through a cycle of slumber, growth, harvest, then slumber. This time of year the vines are in a critical and fragile state. Budbreak and flowering are beginning to take place, getting ready for a new crop of grapes, and ultimately the next wine vintage.

Last weekend (Easter, April 8th) I was up in the Central Coast, and spent some time wine tasting, as well as taking a look at the vineyards, to see where we were in the cycle. So far, this winter, and early Spring, have been pretty dry in California. Even so, the vines have started pulling up water from the earth, preparing for production. "Budbreak" is when the tiny buds on the vine begin to swell and create shoots and eventually leaves, that help the photosynthesis process.

The soil temperature and the grape variety will determine where budbreak will occur first. Warmer soils will encourage earlier budbreak, than those in cooler soils. Even the soil type makes a difference. Clay soils tend to be cooler, and retain more water. These soils will delay budbreak, versus rocky soils which can actually retain the suns energy, and are warmer. Usually, the daily temperature needs to exceed 50 °F

Syrah, just starting to bud

The type of grape variety also has an impact on when budbreak will occur. Some early budding varieties are: Chardonnay, Pinot Noir, Merlot, and Zinfandel. These are also early ripening varieties. Some early budding, but late ripening varieties are: Reisling, Chenin Blanc, Grenache, and Sangiovese.

On the other end of the spectrum are the late budding varieties like Sauvignon Blanc and Syrah. Both of these are also early ripening. The best known variety that is both late budding and late ripening is Cabernet Sauvignon.

Obviously, soil, climate, and aspect of the terrain are important factors in determining which varieties are best suited for planting.

The vineyard manager needs to watch his vines. Certain decisions must be made at this time, including the first fungicidal spraying (usually a copper based product). If the vineyard is biodynamic, a entirely different set of decisions will be made. Weather during this time is critical. Frost danger still exists, and once the buds push through, they are at risk of freezing. Last year, a deep frost at this time of year, wiped out about 35% of the central coast crop. So, why not try to delay budbreak? Well, if it occurs too late, the grapes might not have enough time to fully ripen, before the fall rains come, and the grower will be in an uncomfortable position of gambling on longer hang time, or picking unripe grapes, or even worse, loosing an entire crop. Just like this time of year, frost or rain at harvest can also have devastating consequences.

Viognier - with embryo clusters

While in the vineyards, I took a look at different grape varieties, all at various stages of growth. At one stop, there were three different varieties planted next to each other. The Syrah grapes were just beginning to bud. If you look very closely at my photos, you can also see how the tiny buds shown are pink, which is an indicator that bud break has recently occurred. Just across the road (literally 20 feet away) the Viognier grapes have fully budded, and are beginning the embryo bunch stage.

The embryo bunch stage is also a very critical part of the grape life cycle. These small green clusters are going to be the flowers that will eventually become the grapes. These are the first indication of the potential size of the crop. Usually, within eight weeks after budbreak, the tiny embryo clusters develop into flower clusters. Since we are not yet in the full flowering stage (usually some time in May), I will defer the discussion of the flowering stage for another article. But again, just like the budbreak stage, this time of year runs the danger of rain, wind and frost. Additionally, the vines can be affected by coulure or millerandage. All of these can dramatically affect the years' harvest and grape quality.

Everyone is closely watching the vineyards right now. Those of you who live in California know that we have rain and much cooler weather hitting us right now. The storm on Wednesday (April 11th) saw temperatures drop here in Southern California, and Friday's storm is supposed to be larger and cooler. Keep your fingers crossed. The next month or so, is critical to this years' wine vintage.