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CLONES

When John was ready to plant his vineyard in 1982, he wanted the best Bordeaux varieties – specifically, the clonal selections he’d seen at Haut-Brion.

Unfortunately, none of these vines were available in California at the time. So he went to France and found a source for the ENTAV-INRA vines he wanted. By 1999, John had the vines and the virgin ground he needed to start a nursery with licensed ENTAV-INRA vines, and make these special clonal selections available to others, as well. To really get the significance of what John did, it helps to have some understanding of the difference between a variety and a clone.

A wine grape variety (like Chardonnay) is created through sexual propagation, which is when flower pollen (the male part of the flower) fertilizes the pistil (the female part of a flower) and creates a seed that grows up into a mature vine. The challenge with this method of propagation is that every time you breed one grape variety with another – or even the same grape varieties together – you end up with a new, completely unique vine with its own set of characteristics. It’s just like people… no two siblings are exactly the same, even if they have the same parents.

Today we have 1,500 unique varieties, derived from 1,500 germinated seeds of the Vitis vinifera species. These modern varieties were developed over many centuries, as people selected for plants that created fruit with the most desirable qualities and grew in the right conditions.

Lucie Morton, a hugely respected viticultural consultant and one of the few ampelographers (experts who identify and classify grapevines) in the U.S., has explained it like this: “Once people decide they like a variety, then they take cuttings from the mother vine to create daughter vines that are 'clones' of that mother vine. This is known as vegetative propagation rather than sexual."

Over many years, those clonal daughters of the same mother may develop subtle differences from one another. For example, a slight change in the terpenes or phenolic components that make up flavor or aroma, which results in a different character of fruit. These are not a change in the DNA per se... but they are something different. With many of these specially developed clones, the differences are sought out and propagated as clonal selections at grapevine nurseries, just like John did at his own nursery in the mid 80s with the certified ENTAV-INRA grapevine clones.

Growers frequently will select multiple clones of the same variety to achieve certain wine styles, and also complexity. These days, the buds from a clonal mother vine are almost always grafted onto a phylloxera-resistant rootstock.

John wrote and published a professional reference book on clones, with research help and translation of the original French papers by winemaker Philippe Melka. It’s called A Concise Guide to Grapevine Clones for Professionals, and you can get your digital copy here