The summer surge: understanding the vigorous growth of vineyard vines

Summer is a crucial period for vineyard vines, characterized by rapid growth and dynamic changes. This is why this unusual weather at the moment is quite challenging for our big littles vines! Sun is finally here, but for how long? Anyway...

This season is marked by the remarkable expansion of the vine’s foliage and the development of grape clusters, all of which are essential for producing high-quality wine. Let's delve into the vigorous summer growth of vineyard vines, the factors influencing this growth, and the techniques used to manage it effectively.

The vigorous growth of vineyard vines

Vineyard vines are renowned for their rapid and robust growth, particularly during the summer months. This period is when the vines exhibit their most dynamic vegetative and reproductive activities.

1. Leaf and shoot development: During summer, the vines produce a dense canopy of leaves. The leaves grow larger and more numerous, maximizing the plant's ability to photosynthesize and produce the sugars necessary for grape development. The shoots can extend rapidly, sometimes growing several inches in a single day.

2. Grape cluster formation: Concurrent with the growth of leaves and shoots, the grape clusters begin to form and develop. This stage is critical as the quality of the grape clusters directly impacts the quality of the wine. What's interesting this year compared with last year is that, at the same time, véraison had got off to a good start (green and purple berries on the same bunch of grapes!). This year, the berries are still green but are growing well.

3. Energy accumulation: the extensive leaf area allows the vines to capture more sunlight, converting it into chemical energy through photosynthesis. This energy is stored and later used for grape ripening.

Factors influencing growth

Several factors contribute to the vigorous summer growth of vineyard vines:

1. Temperature: warm temperatures in summer accelerate vine metabolism and growth. Optimal temperatures range between 25-30°C (77-86°F) during the day, which are ideal for photosynthesis and vine development. These are temperatures that have not been consistently reached here, and we were rather below the averages of previous years. Nevertheless, the vines found the strength to grow significantly. What fascinating plants!

2. Sunlight: long daylight hours in summer provide abundant sunlight, crucial for photosynthesis. Vines positioned to receive maximum sunlight will grow more vigorously. Similarly, even though the sun hasn't been as intense over the last few days as in previous years (especially 2022 and 2023), our vines have made the most of the hours of sunshine to ensure their growth!

3. Water availability: adequate water supply is essential for vine growth. While vines are generally drought-tolerant, controlled irrigation ensures they have sufficient moisture to support their rapid growth without becoming waterlogged. With the last few weeks very wet and lots of rain, we've got just what we need in our vineyard!

4. Nutrient-Rich soil: the availability of essential nutrients in the soil, such as nitrogen, potassium, and phosphorus, supports healthy vine growth. Vineyards often employ soil management practices to maintain nutrient balance. That's what our fabulous clay-limestone terroir with its iron dross provides.

What is 'Effeuillage'?

While vigorous growth is beneficial, it requires careful management to ensure the vines produce high-quality grapes. One crucial technique used during summer is effeuillage (leaf thinning). It involves the strategic removal of leaves around the grape clusters. This practice enhances sun exposure and air circulation around the developing grapes, which is crucial for several reasons to improve sun exposure and to prevent some disease such as Botrytis. It is typically performed after the grape clusters have formed but before they begin to ripen. Leaves are carefully removed to ensure that the grape clusters receive optimal sunlight without overexposing them to harsh sun, which can cause sunburn.

The goal is to maintain a balanced canopy that allows sufficient light penetration while protecting the grapes from excessive heat and UV radiation. This balance is critical for producing grapes with the desired characteristics for wine making.

For the moment, we don't know if we're going to use this process, but it's quite likely given the current climate. We'll keep you informed, of course!