Earliest Recorded Blossoming of Grapevines in Germany

MAINZ, 04.06.07. Actually, the flower clusters of grapevines are rather inconspicuous. Botanically, the clusters are panicles – loose, irregularly branched flower clusters – with individual flowers, or blossoms, on the end of each branch. If successfully fertilized, these blossoms ultimately develop into berries/grapes.

Blossoming – A “Quiet Happening” Decisively Influences a Vintage

Grapevines are “practical” in that many have the ability to self-pollinate, and thus are not reliant on outside help from insects or animals. In all, the overall number of clusters provides an early prognosis in terms of potential yield – with emphasis on “early” – weatherwise, and in terms of pests and disease, much can happen between blossoming and harvest to totally change this first outlook.

Büscher adds: “The next few days are extremely important. Temperatures should not fall below 15°C (59°F).” Furthermore, rainy weather is not good, because cool, rainy weather hampers optimal fertilzation and/or immature berries dry up and fall off the vines – a phenonemon known as “coulure” or “shatter.” Deficient fruit set naturally reduces potential yield.

It’s understandable that vintners follow the flowering period quite closely. In some villages there are “blossoming festivals”! From the end of blossoming it is about 95 days until harvest. The “baby” berries continue to develop from late June til early July and begin to ripen in mid-August.

Actual development depends on grape variety as well as weather conditions and microclimate within a site. But blossoming is the “birthday” of the new grapes – and thus the start of vintage 2007.

Background Info

The Grapevine – Botanical Overview

Originally, grapevines grew in forests and climbed up trees, as “creepers,” members of the high-climbing woody vines known as liana. The earliest findings of grape seeds stem from the early Tertiary Period (ca. 80 million years ago). Wild grapes of the species vitis silvestris and vitis caucasica still thrive in the Upper Rhine, Switzerland and Balkans.

Today’s wines stem from the species vitis vinifera that are the result of specific breeding, accidental crossings and natural mutations. About 8,000 different varieties are known. Grapes grow in the northern hemisphere between the 30th and 51st degree of latitude and between the 30th and 40th degree of latitude in the southern hemisphere.