With the risk of extreme cold nights diminished, pruning the grapevines is in full swing. As the temperature slowly warms up, dormancy is broken and the sap starts to rise in the vines, with the promise of life in the vineyards to come.
Growers finish pruning their grapevines and begin to secure the vines onto the trellis; this process is called tying. Growers try to complete the tying before bud break, to minimize vine damage. As the month continues and vineyard soils start to dry out, growers clean their vineyards by removing cuttings or mulching them in the fields, returning nutrients from the canes back to the earth.
This is bud break month. As the temperatures climb, the rate of growth in the grapevines accelerates rapidly. By the end of May, this growth could reach an inch or two a day. The soil that was hilled up in the fall around the base of the vines to protect them is now removed, as are any weeds that have started to grow. Since weeds compete with the vine for nutrition and soil moisture, weed control is an important cultural practice. In May and throughout June, growers work the soil, allowing it to heat up and incorporate oxygen into its composition. This encourages vine growth.