What a difference two weeks makes

Two weeks ago, I posted a series of autumn foliage pics, one of which is below:

I walked back past that spot yesterday, on an ultimately fruitless quest to take some good sunset pictures. I was stunned by how much more fall-like the vineyard felt after two weeks that included a few days of rain and several nights below freezing.  The new view:

November is a month of dramatic transitions in the vineyard, as the grapevines go dormant for winter and the cover crop starts to sprout after our first significant rainfall.  In two more weeks, I expect to see a faint carpet of green between the rows.

It's obvious that the rainfall is necessary for the next year's vigor of the grapevines.  It's perhaps less obvious that the frosty weather is also important.  Grapevines are deciduous plants, that evolved in a part of the world where warm to hot summers were broken by winters that regularly saw below-freezing temperatures.  The frosts kill off any active growth, forcing the vines to conserve energy in their roots for the next year.  In climates where winter freezes are rare, vines can expend valuable energy on pointless growth in fall and winter, and have less vigor for the following spring.  So while we may lament the loss of the colors of autumn, the transition to the subtler browns and greens of winter is a natural and necessary part of the annual cycle.