2015 25.2 Grape Pruning & Vineyard Management

Grape Pruning & Vineyard Management

Gleanings from a Winter Workshop at Bainbridge Vineyards

A small, highly interested group gathered at Bainbridge Vineyards on February 10, 2015, to sharpen their grape pruning techniques and learn about overall vine management in Western Washington. The workshop was facilitated by both Betsey Wittick (Bainbridge Vineyards) and Mike Lempriere (Perennial Vintners). For the first half the day, Betsey and Mike discussed grape growing in Western Washington and explained the overall pruning process—from equipment used through to where to make the cuts. They discussed the wine grape varieties which work well in Western Washington, such as ‘Madeleine Angevine’ and ‘Siegerrebe’— both early ripening whites. Red varieties included ‘Dunkenfelder’, ‘Agria’, and ‘Pinot Noir,’ though both Betsey and Mike remarked that ‘Pinot Noir’ tends to require attention and extra care to thrive. The basic tip provided was to pick varieties that ripen well in your climate, whether for making wine or eating fresh (in the case of table grapes).

Betsey and Mike explained the different types of wine growing climates, sourcing grapes, and how to calculate Growing Degree Days (GDD) for determining the best suited varieties. Along with GDD, getting to know your site is an important first step for planting grape vines. South facing slopes are the best scenario for maximizing growth in the Western Washington climate. Betsey explained the process of preparing the soil for planting grapes and for sourcing plant material.

Grape vines that have been grafted on to phylloxera resistant rootstocks are always a good idea. It is also possible to root cuttings from pruned, one-year old wood. Betsey showed examples of one-year wood versus two-year old wood and explained the process of growing grape plants from cuttings. Once cuttings have rooted and moved to their site, take the first two years to allow the small plants to develop their root system. Mike suggested irrigating for the first year, but after that allowing the grapes to find their own water. At the end of the third year, the grape plants can be put onto a trellising system, and in year four, one can allow the plants to fruit. At the end of year four, the plants can be cane pruned—a technique used for early ripening varieties. This differs from spur pruning, which is common in the warmer growing regions of Washington such as the Columbia Basin and Yakima Valley. In cane pruning, the trunk is the only part of the plant that stays from year to year whereas with spur pruning, the “arms” that extend from the trunk are left on the trellising wire.

Betsey illustrated cane pruning before everyone ventured into the vineyard for hands-on practice. She showed the group a grapegrowing poster which depicted all the tasks needed to maintain grape vines over one season—there were 27 different tasks! Betsey shared what she tells all her interns: “After you’ve grown grapes for a year, you’ll never look at a glass of wine the same way.”

Attendees spent the afternoon in the vineyards, practicing cane pruning on ‘Madeleine Angevine’ grapes—a variety that Betsey assured everyone was very forgiving. The plants had already been rough pruned (the process of pruning out extra fruiting canes from the previous season) to four, one-year old canes from which the new “arms” would be narrowed down. Both Betsey and Mike guided participants in choosing the two, one-year old canes from which the fruiting canes will grow in the coming season. These canes are bent down from the trunk, wrapped around the trellising wire, and secured with a twist tie. Sometimes canes break during this process, which is why four canes are kept during rough pruning to make sure there are back-ups. After practicing pruning, Betsey took attendees around the vineyard showing the 20+ year old block of ‘Siegerrebe’ grapes that she herself prunes. She also maintains soil fertility by using cover crops in the alleyways between rows. The group walked next door to Mike’s vineyard, where he explained the decisions he made in utilizing his site (a former Christmas tree farm). Mike also maintains a small nursery of grape plants.

Back at Bainbridge Vineyards the group tasted a few of the wines —a wonderful way to end a hands-on experience! After a glimpse of what it takes to maintain a vineyard, everyone sure appreciated the complexities of these Western Washington grown wines even more. Cheers!

Summary by Angela Anegon, Tilth Producers’ Education Coordinator. Angela is excited to be planning more hands-on workshop opportunities.

This workshop funded in part by a grant from the WSDA Specialty Crop Block Grant Program.

Tags: Bainbridge Island, Grapes, Pruning, Vineyard