A Wet Winter in the Vineyard

Many of you have heard a lot about the historic drenching most of California received this winter firsthand. Even if you don’t live here, you’ve probably become familiar with the term “atmospheric river” that’s all over the national news describing the series of intense storms that have blessed (cursing?) our drought-stricken state over the last five months.

How does rain affect grapevines?

People have been kindly reaching out to ask about the vineyards through all of this rain this past winter, and the good news is that vines are dormant through the winter and safe from rain until flowering, which occurs later in May. Rainfall is essential to grapevines, even if they are one of the planet’s sturdiest, drought-tolerant plants. And luckily, rainfall that occurs in the dormancy cycle of the vine, when California typically receives most of its annual rainfall, makes fine wine growing in our region possible. 

As of March, the Russian River Valley appellation where Charlie Chenoweth’s Bootlegger’s Hill Vineyard and our family’s soon-to-be planted vineyard has received a lot of rain. Flooding and heavy rains in a short time pose a risk to vineyards if debris or heavy flows disrupt established vines.

How does rain affect wine quality?

Nearly all of California’s quality wine-growing vineyards use precision drip irrigation to control how much water vineyards receive during the growing season. Drip lines on each vineyard rows can even be controlled vine by vine if soils or slopes give one portion of a row naturally holds more water due to its soil composition or 

Soil conservation and erosion control in vineyards

Preparing a vineyard for the rainy winter season starts even before it is planted. Surveys of the surrounding land, hillsides, creeks, and slopes inform how a property will be planted. Plotting out the direction, length, and width of the vineyard rows is an important consideration and depends on how water flows on any given piece of land. At our vineyard in Sebastopol, creating a level planting field that allowed the vines to send deep roots meant moving TONS of rock that changed the landscape and how water would penetrate and flow.

Some key soil conservation and erosion control measures include creating diversion ditches with drains and tiles to direct runoff water into nearby culverts or streams. Cover crops between vine rows and on unplanted vineyard lands are used to reduce erosion and conserve and nourish the soil. Straw wattles, the round worm-like bundles you may see snaking around vineyards, are placed to control runoff. Mulch and gravel or stone on vineyard roads and perimeters also reduce soil erosion and flood danger.

Ultimately, this season of heavy rains will make the vine roots grow even deeper, which helps them find water in years when the rains aren’t quite so plentiful.