Pruning is one of the most critical operations carried out in vineyards. In viticulture, pruning refers to removing unnecessary shoots and canes that have grown over the season, leaving only those required for the coming production cycle. This work is performed mainly from winter through early spring.
The history of pruning is long, and its necessity is said to have been clearly described as early as the Roman era. Because grapevines are climbing plants, they will continue to extend their shoots indefinitely if left unmanaged. To cultivate vines within the constrained space of a vineyard, pruning is indispensable.
In recent years, this long-established practice has attracted renewed attention. A major driver is a pruning philosophy known as Gentle pruning (GP), which focuses on vine continuity and long-term viability. Alongside the emergence of technical consultants who have systematized practical pruning methods based on this philosophy, GP appears to be steadily spreading into commercial viticulture.
This article revisits the fundamentals of pruning in winegrape production—its meaning and historical context—and clarifies what Gentle pruning is as a concept and as a set of practices.
The Meaning and Objectives of Pruning in Viticulture
In fruit production, pruning is the operation of removing unnecessary growth and retaining only the structures that are needed. The aims include optimizing the use of limited space and improving the vineyard microclimate by arranging shoots and clusters in a deliberate spatial pattern.
Grapevines are climbing plants with limited self-supporting capacity. If left unmanaged, shoots continue to elongate and spread, often creeping along the ground. To lift and position vines along a support system—posts and wires—and to keep growth within a defined training space, pruning and training are essential.
The role of pruning extends beyond canopy positioning. Pruning strongly influences yield regulation, vine vigor management, and the quality of the grapes harvested.
In practical pruning, the key metric is the number of buds left on the retained canes or spurs. For grapevines, the number of clusters borne on a shoot is broadly predictable. Therefore, once bud number is set, the number of shoots that will grow is largely determined, and the number of clusters available for harvest in autumn is also largely determined. In other words, the season’s potential crop is decided, to a considerable extent, by early spring—before the season is fully underway.
Moreover, fixing the expected number of clusters and shoots also largely constrains vine vigor. A vigorous vine can be left with more shoots, whereas a weak vine is typically pruned to fewer shoots. By adjusting bud number through pruning, growers regulate vine vigor.
The Reassessment of Pruning Methods and Its Historical Background
Pruning has often been discussed primarily as a tool for labor efficiency and yield regulation. In recent years, however, a further perspective has become increasingly prominent: extending the productive lifespan of grapevines.
Gentle pruning is positioned as a pruning philosophy that focuses directly on this longevity perspective.
One reason this approach has attracted attention is the increasing severity of Grapevine Trunk Diseases (GTDs) in many winegrowing regions worldwide. One estimate suggests that in France, GTDs—typified by Esca and Eutypa—have rendered approximately 13% of vines unproductive.
Traditionally, GTDs were understood largely as diseases caused by fungi entering the vine and establishing within woody tissues. More recently, this view has been reconsidered. A growing body of discussion suggests that fungal invasion may be secondary, and that a more consequential driver is xylem damage caused by pruning. Under this hypothesis, pruning wounds first induce necrosis in woody tissues, and fungi subsequently colonize these necrotic zones, leading to disease expansion. This mechanism has not been fully proven, but recent case studies have reported results consistent with this interpretation.
The Focus on Sap Flow
A practical way to think more concretely about pruning-related xylem damage is through sap flow and the size of pruning cuts.
After pruning, drying progresses inward from the cut surface—the pruning wound—into the cane or arm. Because this drying typically forms a conical shape with the cut surface as the base, it is termed the desiccation cone. The formation of a desiccation cone disrupts sap flow in that region and promotes necrosis. The depth of the desiccation cone is generally considered to correlate with the size of the cut.
Because pruning necessarily creates wounds, the formation of desiccation cones cannot be fully avoided. However, if the desiccation cone progresses extensively, the worst-case outcome can be dieback affecting a large portion of the vine. To reduce this risk, pruning approaches have been proposed that aim to keep cuts small and to avoid obstructing sap flow.
This philosophy and the associated techniques are referred to as Gentle pruning, respectful pruning, or sap-flow-respecting pruning. The term soft pruning is also used. In practice, these labels generally refer to the same underlying pruning concept.
It is important to distinguish this approach from minimal pruning, which is a different pruning method. The term Simonit & Sirch method is also sometimes used, but this refers to a specific consultant group that has formalized and branded its own approach. While there are conceptual similarities, Gentle pruning is not synonymous with the Simonit & Sirch method.
A Recurrent Cycle of Reassessing Pruning Practices
Pruning as a technique has been advocated since the Roman era. In Mediterranean regions in particular, training systems that concentrate pruning wounds on one side of the vine—thereby minimizing disruption to sap flow—have been transmitted over centuries.
The first major modern trigger for a reassessment of pruning methods is often said to have been the damage caused by phylloxera (Daktulosphaira vitifoliae). In the late nineteenth century, the use of rootstocks became widespread to mitigate phylloxera damage.
Grafting European Vitis vinifera cultivars onto American rootstocks not only reduced phylloxera losses but also increased vigor in many vineyards. With stronger growth driven by a different root system, traditional pruning methods were no longer sufficient to control vigor, and more severe pruning became common. Although vigor could be constrained in this way, growers then began to observe and problematize vine decline and weakening.
In response, pruning methods aimed at reducing damage to the vine were proposed in the early twentieth century. These approaches drew on older practices and represent a conceptual foundation for what is now called Gentle pruning. It was also during this period that the Guyot Poussard training and pruning concept was advocated.
This trajectory shifted again in the late twentieth century. From the 1960s onward, vineyard management increasingly prioritized productivity and cost reduction, and pruning practices emphasizing work speed became dominant. Traditional knowledge associated with more conservative pruning gradually faded, and severe pruning re-emerged. This shift is regarded as one contributing factor to the GTDs problems that persist today, and it is against this background that a renewed return to traditional insights is now being pursued.
Although Gentle pruning has attracted attention in the last few years, the concept itself is not new. It can be understood as a scientific re-evaluation and re-organization of long-standing technical knowledge and practices.
Sap Flow as a Framework for Extending Vine Longevity
While vine mortality due to GTDs is widely recognized as a serious issue, premature vine aging has also long been understood as a practical challenge in vineyards. A key point here is the economic impact of reduced production efficiency.
When a vine dies, missing plants must be replaced. However, even after replanting, there is typically no harvest from replacement vines for the following three to five years. Even when vines do not die outright, progressive aging commonly reduces yield, and economic performance declines accordingly.
Even aside from GTDs, vine aging has often been treated as unavoidable. To avoid productivity losses associated with aging, many wineries and growers replant vineyards on a regular cycle. In this sense, aging and the costs of replanting have long been treated as necessary operating expenses in vineyard management.
Recently, however, it has been suggested that pruning may contribute to mechanisms that accelerate this aging process.
Prior studies have reported that, under experimental conditions, desiccation cones formed by pruning reduced sap flow by approximately 35–40%. It has also been reported that the formation of desiccation cones within woody tissues is accompanied by substantial consumption of stored reserves.
When sap flow is impaired, it becomes harder for water and mineral nutrients taken up by the roots—and carbohydrates produced through photosynthesis—to be transported to the sites where they are needed within the vine. The nutritional deficit that results is commonly compensated by mobilizing stored reserves within the vine. However, as noted above, disruption of sap flow itself can become a driver of reserve depletion. Therefore, when pruning obstructs sap flow, the consumption of stored reserves can become far greater than it would be in the absence of pruning-wound effects.
Stored reserves are a crucial nutrient source from budburst to leaf expansion in early spring. Because inflorescence development is also considered to proceed during this period, depletion of stored reserves can have substantial negative effects, from vegetative growth through to yield. Moreover, poor growth delays the replenishment of depleted reserves, which increases the likelihood of long-term nutrient exhaustion and, ultimately, may accelerate vine aging.
Because pruning is unavoidable, the complete elimination of desiccation-cone formation within woody tissues is not possible. Nevertheless, by modifying pruning practices, it is thought to be possible to return the progression of aging—previously accelerated under certain practices—closer to its inherent rate. As a result, the productive lifespan of vines may be extended, improving the long-term continuity of the vineyard.
Gentle Pruning as a Philosophy and a System of Practice
Gentle pruning, which has regained attention through recurring historical cycles, is not a term that denotes a single discrete technique. Rather, it refers to an entire pruning system encompassing both philosophy and practice. The philosophy is to maintain vine health and extend productive lifespan; the practice consists of working methods that respect sap flow.
Several aspects matter in applying GP, but the core ideas can be summarized in three points.
First, if pruning is performed, the formation of desiccation cones is unavoidable.
Second, sap flow is disrupted in the area surrounding a desiccation cone.
Third, indiscriminate pruning wounds increase the depth of the desiccation cone, i.e., they deepen dieback.
In practical terms, implementing GP means focusing on how to minimize the effect of inevitable desiccation-cone formation on sap flow and how to prevent the progression of dieback. The approach proposed to achieve this is to concentrate pruning wounds on one side of the vine.
Pruning Methods That Do Not Obstruct Sap Flow
When a cane is cut, a pruning wound is created, and the desiccation cone forms from that wound. As repeatedly emphasized, eliminating desiccation-cone formation is not possible given the physiological characteristics of grapevines. In addition, sap flow generally occurs only a few millimeters beneath the surface of the woody tissues. Therefore, even if a desiccation cone is shallow, once it forms it will disrupt sap flow.
Given these constraints, pruning in a way that further avoids disrupting sap flow requires a deliberate trade-off: sacrificing some flow pathways to protect the pathways that matter most.
To examine this, consider sap flow in grapevines. Sap flow is fundamentally upward, from the roots toward the canopy. This is because the vine relies on the negative pressure generated by transpiration from leaves to draw water upward from the soil. Put simply, in grapevines the leaves function as the pump that pulls water upward.
Because leaves are located on shoots in the upper portion of the plant, water absorbed by the roots is pulled upward toward the leaves. In this process, sap does not primarily travel through the center of the trunk; it moves through tissues close to the surface.
Once this structure is understood, the spatial arrangement of the most important flow pathways also becomes clear. Whether the training system is Guyot or Cordon, in a vertically trained trellis the outer side—or, depending on the geometry, the lower side—of arms and canes consistently functions as the prioritized sap-flow pathway. These are the pathways that must be protected; more specifically, they are the pathways where pruning wounds should not be created.
At the same time, shoots must be removed, and shoots must also be grown to obtain a crop. The proposed solution is to consistently grow shoots on the inner side or the upper side, and to prune those shoots in turn. By doing so, pruning wounds are consistently concentrated on one side of the vine—and specifically on the side that is less critical as a sap-flow pathway. Repeating this pattern concentrates pruning wounds on a single side, making it possible to prune in a way that avoids generating desiccation cones on the opposite side.
Can Gentle Pruning Become a “Savior”?
In Europe, where GTDs have imposed severe pressure on viticulture, GP is recognized as a highly important system. However, it remains uncertain whether this pruning framework is universally applicable across all wine regions worldwide.
Case studies evaluating pruning methods that maximize respect for sap flow have reported several outcomes. One is that this approach tends to increase vine vigor. If one assumes that desiccation cones have been suppressing vine vitality, this may not represent a “strengthening” so much as a return toward the vine’s baseline condition. Nonetheless, in comparative terms, the vine will be experienced as more vigorous. This implies that in regions where vines are already highly vigorous, adopting this pruning approach may lead to excessive vigor that becomes difficult to manage.
In addition, the relationship between GP and disease incidence has not yet been fully elucidated. It is not currently known whether GP can truly suppress GTDs. At the same time, some reports suggest that there may be diseases that are more readily suppressed and others that are less affected. If the primary goal in changing pruning methods is to control GTDs, these observations imply that GP may not necessarily be the correct solution in every case.
Creating a clean pathway by avoiding sap-flow obstruction also implies increasing the speed of sap movement. One might compare this to rebuilding a narrow, winding road into a wide, straight highway. In vineyards that have suffered from insufficient flow, such a change can represent a major improvement. Conversely, in vineyards where an inherently strong flow has been structurally moderated—resulting in an appropriate effective level—removing that moderation could plausibly lead to excessive outcomes.
Furthermore, a situation in which sap circulates smoothly also implies that everything carried in the sap circulates smoothly through the vine. This “everything” includes not only nutrients but also elements such as viruses, whose dissemination within the vine is undesirable.
Replanting due to vine aging undeniably imposes substantial costs on wineries and growers. From a purely financial perspective, extending vine lifespan and obtaining more harvest from each vine can be considered a rational management strategy.
At the same time, it should not be overlooked that regular replanting has also helped suppress the spread of fatal diseases and excessive soil fatigue. Replanting on a periodic basis has also played a non-trivial role in adjusting cultivar composition in response to changing circumstances. Because the direct and indirect costs are large, regular replanting is often viewed primarily through its disadvantages. However, rejecting it unilaterally can create unexpected downsides.
There is, admittedly, a certain romance in vineyards planted with vines that remain productive for several decades. Some stakeholders also regard old vines as one benchmark of quality. From that perspective, keeping vines productive over a longer period through GP can offer meaningful advantages.
Yet the crucial question remains: is this truly the best choice for one’s own vineyard? In some situations, it may be more appropriate, at the level of overall system design, to accept replanting after a defined period as an explicit premise. In the contemporary context—where external factors, including weather patterns, change rapidly and often faster than viticultural systems can adapt—such a line of thinking may also be necessary when considering pruning decisions.
