After the busy harvest season, when the fruits of our labour are aging in barrels (literally), the vines have lost their leaves and become dormant. Although the vines are “sleeping” if you will, our vineyard team are still hard at work, preparing for the upcoming growing season.
WHAT IS PRUNING & WHY DO WE DO IT?
The main goal of vineyard management is to achieve a maximum yield at the desired quality.
Winter pruning is a crucial aspect of the grape production system while the vines are dormant. This process maintains the training system, allows one to select the one-year-old fruiting wood, and controls the potential quantity of fruit produced.
Pruning must take place annually. Fruit is only produced on shoots growing from one-year-old canes. Therefore, healthy new canes must be produced every year to maintain annual production of fruit. Pruning is used to remove unnecessary canes and to retain a small number of good ones, which has a large influence on both yield and quality.
It encourages the vines to grow a structure that is conducive to harvesting, while also helping to shape the location and overall development of the canopy. Too many buds can result in a crowded canopy with excessive shading and a high crop load that the vine may not be capable of ripening. When a canopy is properly constructed, it has a great influence on overall grape yield, health, and development.
The overall goal of winter pruning is to prep the vines for the growing season ahead.
WHEN TO PRUNE
Winter pruning takes place during the winter, as the name suggests. At this time, the vines are dormant and the canes are woody. Pruning while the vines are dormant and have no foliage, allows for easier wood selection and cane tying. In the fall, the vines start moving complex nutrients and minerals through the vascular system from the leaves, down into the permanent wood (roots, trunk, cordons). Premature pruning can disrupt this transfer of nutrients, creating a deficiency for the next growing season. Pruning too late, however, can sometimes cause bud break to start later than desired which can negatively affect the entire growing season.
HOW WE PRUNE
During pruning, we remove canes, in turn removing buds that would otherwise become new fruit producing shoots the following season. By removing buds, we ensure concentrated growth within the remaining buds, and eventually, canopy and fruit development.
During winter pruning, 70-90% of the previous season’s vine growth is removed. Vines typically have 100+ buds, however, after winter pruning, that number drastically decreases to around 30 -36 remaining buds.
Over and under-pruning can lead to an unbalanced vine and grape development. Over-pruning can result in a nutrient and mineral deficiency, where the remaining buds might not provide enough nutrients and minerals to fully ripen the fruit. Also, during dormancy, important nutrients and minerals are stored in all woody parts of the vines, so when the woodier material is removed, fewer nutrients and minerals are left for the upcoming growing season. Under-pruning the vines can result in an excess of vegetative growth which leads to uneven fruit development.
Selecting how many buds to leave per spur depends on many different factors and can change from season to season. Typically, the younger the vine is, the fewer buds left per spur. As the vine grows and matures, more buds are left per spur until vine and grape development are at an achieved balanced state. Climate and soil fertility effect vine strength and growth, which in turn can be controlled by bud selection. The type of grape varietal also influences bud count determination.
At our Monte Creek vineyard, on average, Vitis Vinifera vines can be pruned to 16 – 18 buds per vine; whereas, our cool climate vines are often pruned to 20 – 22 buds per vine. It’s also important to note that just because we pruned a certain way this year, does not necessarily mean that we will prune to the same count next year. Bud count selection is not a set number or formula from one year to the next. If vines endure damage over the winter due to frigid temperatures, fewer buds may need to be left untouched in order to reach proper vine and grape development.
All in all, winter pruning is the first step in a growing season – a process implemented to achieve vine balance and optimum grape development. When properly pruned, shoots can be controlled, allowing the vine to fully ripen its fruit to the desired yield. In addition to, and as equally important as consistently ripening fruit from one year to another, is the overall long-term health of the vines at our Monte Creek and Lions Head vineyards. It is this consistent fruit production that provides Monte Creek Ranch Winery with the quality and essential foundation on which we produce our award-winning wines.
Buds – One or more embryonic shoots protected in a series of modified leaves called bud scales.
Bud Break – When buds begin to swell and grow.
Cane – The vine shoot from the period it matures and lignifies (turns brown and woody) until the end of the second year of growth.
Canopy – The foliage cover of the vine.
Cordon – An arm or trunk extension positioned horizontally or at an angle to the axis of the trunk.
Spur – A short cane possessing the desired bud count.
Trunk – The vertical wood stem of a vine up to the origin of the branches.
Yield – The fruit crop per area planted.