Vines

June 6, 2018January 10, 2024

Vineyard Terminology – Vine maintenance

Welcome to the third installment of our Vineyard Terminology series: Vine Maintenance!

Once training and pruning systems are established, the vine must be kept clean to ensure only the desired amount and quality of fruit is produced.

Shoot thinning:

Grape vines are very tenacious in their growth and will attempt to grow from all parts of the vine, not just the areas you have selected during pruning. Shoot thinning is the process of removing green growth from parts of the vine that were not intended for fruit production, such as secondary shoots (a shoot that has emerged from a bud that was not seen or removed during pruning) or shoots on the undersides of cordons/canes. Shoot thinning is best done when the new growth is only about 6 inches long, as the unwanted material can be broken off with bare hands, as opposed to clippers or a knife. Some varieties require more thinning than others, and may even need multiple passes as the growing season progresses in order to keep the vine clean and balanced.

Suckering:

Suckers are shoots that have grown from either the trunk or under the soil level. These shoots are problematic since they do not produce much fruit (if any), they suck (hence the name sucker) resources from the main vascular system of the vine, and they make the vine look unkempt and messy. Suckering should take place either in conjunction with or very soon after shoot thinning, in order to allocate the most of the vines resources to leaf and grape growth in the fruiting zones.

Crop thinning:

Most winemakers and vineyard owners want to make sure that their vines are producing only the best quality fruit possible, so sometimes clusters must be removed to concentrate the flavors and resources in the remaining fruit. Crop thinning can be accomplished by selective shoot thinning, or by simply clipping unwanted clusters from the vine, though the latter method is extremely time consuming. The amount of fruit that a particular vine can handle varies greatly with varietal, location, rootstock, soil, training system, and climate. Some varieties, such as Zinfandel, will produce extremely large amounts of fruit (upwards of 20 tons per acre), if left to their own devices. While this level of production is perfect for commercial table-wine operations, premium labels often aim for between 2 and 3 tons of grapes per acre. In order to achieve this level or production, restrictive pruning and training systems are coupled with crop thinning early in the season.

June 4, 2018January 10, 2024

Vineyard Terminology – Vineyard Floor

Welcome to part two of our Vineyard Terminology series: Vineyard Floor!

Keeping the vineyard clean and neat helps to reduce competition against the vines and to produce concentrated fruit flavors. The Vineyard Floor refers to both the aisle between vine rows and the space underneath the vines; each of these areas requires different management practices to kept them clean.

Aisles:

There are two main approaches to keeping vineyard aisles tidy: 1) letting the native weeds and plants grow there during the dormant season and mowing them before they can compete with the vines in the spring, or 2) planting a Cover Crop, a mixture of nutrient-rich plants (generally legumes and grains), that can be cultivated into the aisle as a form of organic fertilizer. Both approaches have advantages, and the selection of one over the other is generally the vineyard manager or owner’s decision. Native weeds are easier to maintain since they do not require planting or maintenance (aside from mowing), but they can also leech important nutrients from the soil and pull stored water out of the ground. Cover crops are a good nutritional alternative to fertilizer or soil additives, particularly for organic vineyards that have few nutritional supplement options, but they require a fair amount of labor to establish and maintain every year.

Under Vine:

The under vine area is a critical area to keep free of weeds, but due to the presence of the vines, options are sometimes limited. The most common approach for controlling the under vine space is to spray a mixture of herbicides when the weeds first appear. This will kill the weeds but leave the dormant vines unharmed, regardless of the chemicals used. Organic options for under vine sprays are also available, but generally require more applications. Other options for weed control in this zone include: weed whacking, which is extremely effective, but also very costly for larger vineyards; and cultivation tools, which till the soil to physically remove the weeds and disturb their seeding cycle.

Vineyard Floor management is essential for every vineyard, and the benefits of keeping this area clean can lead to a higher quality wine.

June 1, 2018January 10, 2024

Vineyard Terminology – Parts of the Vine

This is the first part of our multi-post series on Vineyard Terminology.

Understanding how and where your grapes are grown is just as important as knowing how to make those grapes into great wine. To that end, let’s explore some basic vineyard terminology that can help inform your grape-buying decision.

Rootstocks and Clones:

Wine grape vines are often the union of two different types of vine, a rootstock and a clone. Rootstocks often from wild grape varieties that provide inherent immunities or advantages to the vine. Many rootstocks were initially propagated from wild American grapes that were resistant to a pest called Phylloxera that had decimated much of the European wine grape industry in the late 19th century. Modern rootstocks have been adapted for many different situations including: drought conditions (rootstock 110R is the most common for this), wet or high water capacity soils (rootstock SO4), as well as soil acidity or alkalinity. Since rootstocks were created from wild grape varieties, any grapes produced from them are not viable for use; most modern rootstocks are engineered to be infertile in order to prevent any pollination issues in the main varietal.

Once an appropriate rootstock has been selected, a clone must be selected. Wine grape clones simply refer to different selections within each varietal. While there are standardized clones for each varietal that are readily available from most nurseries, there are some regional clones that have been adapted from local vineyards. Even though different clones of the same varietal produce the same type of grape, there are often minute differences between clones.

Rootstocks and clones are joined together via grafting. There are multiple grafting techniques used by nurseries and growers, but the end result is the same: a vine with the resistances and tolerances of the rootstock that produces grapes of the clone’s varietal.

Training:

Vine training describes the overall shape and structure of the vine. The most common training systems are cordon trained (vertical, unilateral, bilateral, and quadrilateral) and head/goblet trained. New vines are trained over the course of 2-3 years, and once established, the vine’s shape is something that will have to be maintained over the life of the vine. Keeping vines well-trained is an ongoing process that is critical not only to a vine’s shape, but also to its health and long-term fruit quality.

Vines, Vineyard — A head trained vineyard in the Sierra Foothills

vineyard, vines, grapes — An example of Bilateral Cordon training in the Sierra Foothills

Pruning:

Pruning is the annual process of selecting which parts of the previous year’s growth you want to keep, and by extension, how much fruit you want the vine to produce this year. The two main pruning methods are spur pruning (both of the pictures above feature spur pruning) and cane pruning. The ideal pruning method for a vine is determined by many factors, including: varietal, location, rootstock, training system, and amount/quality of fruit desired.

Pruning is generally done either after harvest in the fall, or before bud break in the spring. Effective pruning ensures that the vines will only focus their resources on producing the best grapes possible.