Vintage Update – April 2022
Once the vines have been pruned (January and February), last year’s brush has been pulled (February), and the new cordons have been tied down (March), vineyard stewards and winemakers start waiting for the vines to awaken. Up to this point in the year, our vineyards of dormant vines have appeared barren. After the buds have swelled, in April they burst open and will soon reveal the new shoots, leaves and grape flowers for the harvest ahead.
The date of bud burst is highly dependent on elevation and weather. A colder than average winter will slow down the sap flow that brings the vines up from dormancy while a warmer winter speeds it up. This unpredictability with weather is the reason vineyard stewards work long hours in the early months of the year to prepare the vineyard for the next year of growth. Regardless, the lower elevations of the Dundee Hills will see bud break up to two weeks before higher elevations because of the warming soil temperatures.
Buds are quite fragile until the green shoots are slightly more developed, so it’s not uncommon for work on the vines to take a brief hiatus during bud break. In the interim, vineyard stewards focus on undervine care to give the root systems everything they need for a productive harvest. This could include mulching last year’s brush to return nutrients to the soil or, alternatively, burning it in an attempt to prevent powdery mildew spores from spreading and scattering ashes between the rows.
Vineyard stewards will also begin using cultivation tools under the vine to mitigate weeds. Once the weather is warm enough for new growth on the vines, it’s also warm enough for weeds to begin growing, which can cause competition for water and soil nutrients. One commonly used tool for weed control is a French plow, which has a blade that goes under the soil, lifting it up to sever the root system of the weeds. The hydraulic sensor knows when it contacts a vine, allowing it to automatically turn off, swing outward around the vine and then snap back into the row as the machine moves forward.
Once shoot growth begins in earnest, vineyard stewards will begin shoot thinning, a process where some of the buds are removed to ensure the amount of fruit produced is sustainable by each cane. Too much fruit can lead to a lower quality yield and an increase in bunch rot if the clusters are touching. Vineyard stewards aim for roughly 4” between buds, approximately the width of your palm.
Next month, we’ll see leaves beginning to unfurl as well as the development of the inflorescences, the tiny clusters of grape flowers. It won’t be long before grapes are ripening on the vines!