Bud Break in Napa Valley
Spring is here in the beautiful Napa Valley. Long overdue rains finally returned to California in February, and so far, March has been full of sunshine. The vineyards are all neatly pruned now, and the dormant grapevine buds are beginning to swell and open to new green shoots.
The timing of bud break is dependent on the grape variety and vineyard temperature. Here in the Napa Valley, Chardonnay vines are usually the first to wake up and followed by other aromatic white varieties. Bordeaux varieties like Merlot and Cabernet Sauvignon will come out of dormancy several weeks later and are generally the last locally grown varieties to open up.
What’s truly amazing is how much specialized plant material is packed in those little buds. A miniature, embryonic shoot is compressed in the tiny bud like an accordion, and the primordial grape clusters have already been established. Biologically speaking, fruit for the 2014 vintage began production last summer as the buds were formed at internodes along the shoot.
Over the next several weeks we will be closely monitoring nighttime weather for frost events, as the young shoots are very tender and susceptible to frost damage. In the event of a hard frost, growers on the valley floor will use wind machines or sprinklers to help mitigate damage from freezing temperatures. If frost control is absent or insufficient, the grapevines do have a backup system in their secondary buds that will sprout when growth from the primary bud is severely damaged. Luckily for us, the forecast for the next two weeks calls for lots of sunshine with highs in the 70’s and overnight lows in the 40’s; so it’s clear sailing for now.