Wine Dreams

Posts Tagged ‘Phylloxera’

So probably the biggest choice or decision to be made when planting a vineyard is what to plant.  We had some very good information to get us started in our quest.  First we were very sure that Cabernet Sauvignon was our grape of choice.  With that in mind our next question was what type or clone of Cabernet Sauvignon would perform best in our area and maybe even more importantly what rootstock should we use to grow our Cabernet on.

The first question we worked on was rootstock.  Wine grapes are typically European grape varieties.  While they perform very well in the Napa valley, if they were planted naturally on their own roots they would be destroyed relatively quickly by Phylloxera which is a native American soil louse that attacks the roots of grape plants.  American grape varieties have the ability to co-exist with Phylloxera but American grapes don’t make very good wine.  So typically you plant an American rootstock in the ground and then graft a French clone of the grape that you want to grow on top of it.  The rootstock does not affect the flavor or characteristics of the grapes, but it could affect the growth characteristics of the vine.  The goal is to select a rootstock that best fits the soil you have to plant it in, along with the typical growth characteristics of the variety of grape that you will be planting.

Our soil is deep rocky soil which leans more towards the sandy loam and gravel then to clay.  We hope to use as little water as possible with the eventual goal of dry farming if the site will allow it.  To have a chance at accomplishing this we choose a rootstock that is very deep rooting and has great drought tolerance.  The rootstock that we choose is called 110R.

Next is the clone or selection of Cabernet Sauvignon that will be planted or grafted onto our rootstock.  Dr. Steven Krebs from Napa Valley College was very helpful in pointing us in the right direction on this front.  His idea was that we should plant a clone or selection of clones that were breed for the higher temperatures that we would get in Calistoga.  French clones are breed to ripen much faster than American clones due to the lower temperatures in the Bordeaux region of France.  He asserted that when you plant a French clone you will get a very fast spike in the sugar levels of the grapes without the benefit of physical ripeness.   However, the American clones tended to ripen slower since they were used to getting plenty of sun and heat.

With those thoughts in mind we choose to use clones 4, 8, and 30.  Which are all suited to higher temperatures.