Friday, January 22, 2010

What to Plant, Hybrid, Vinifera or both?

I had an interesting conversation with a friend the other day. They were asking me some questions about the vines we were planting at the vineyard. I explained that we had a mix of hybrids and vinifera. I went on to explain that hybrids came about as a result of breeding grape vines for pest and disease resistance and cultural superiority (drought resistance, later bud break, earlier ripening etc. etc.). We talked about grafting of Vinifera to root stock of other grape vines to make the resultant plant better suited to a particular climate, growing area or conditions or disease/pest resistant. My friend asked if these grafted vines were then classified a hybrids. Good question?

I had never thought of it like that before but it is an interesting perspective.

This was a diversion as our discussion was not so much about the differences between hybrids and Vinifera but why the choice of vines we have in our vineyard. There are so many variables that come together that determine what grape varieties are best suited to one location or another. Temperature, sunlight, moisture, frost free days, soil, humidity, pests all play a role in determining what grapes will grow best at a particular site.

We know that we are at the low end of the heat and frost free days spectrum for growing grapes in BC and this means planting the varieties that are the earliest maturing varieties. We are not sure what the winter low temperatures are so this means having vines that are of various levels of cold hardiness.

I think that all the varieties we have decided to plant will work out alright in one way or another. Most are recolgnized varieites (link to VQA varieites) and it appears thusfar that they should all do well in some years if not all. Now there are about the same number of Hybrid grape varieties as Vinifera varieties on the list of acceptable varieties for VQA designation. So while there are alot of options of what to plant, what is important is which varieties will do best at the site. While the Pinot Noir or Zweigelt may do well on an annual basis they may not ripen to as good of sugar/acid levels that you may find at other warmer, longer season sites. Some years may be quite good while others quite poor. In reality you can expect each year is going to be different than the last with some vintages better than others - but this is with varieties that are properly suited to your site.

There is a grower in the south Okanagan that I was talking to who said that he had to over-crop his Seigerrebe to ensure that it didn't ripen too early. He often has to blend it with Pinot Gris to bring the acid up. Even at the right site Seigerrebe is noted for dropping it's acid very quickly and having a high ph at harvest (this is not always desireable in a Germanic style white wine which Seigerrebe is usually made). If the site is too warm and this grape ripens too early this could lower the quality of these grapes at harvest. He said, if you over crop your vines it takes them longer to ripen, but then you can stretch out harvest to when the temperatures are cooler and this can help retain some of the acid and maintain a lower ph. However, there is much literature that suggests that over-cropping results in a loss in quality and can harm the winter survival of the vine or buds.

So even if you have a site with a lot of heat, you have to match the variety to the site. While there are few grapes that would ripen too early at our site, I expect that if we choose varieties that are marginal ripeners for our site then we can expect more poorer vintages than good vintages over time. We are also drawn to disease resistant varieties and that generally puts us in the camp of hybrids.

While there are certain varieities we'd like to grow, and certain varieties in greater demand (which is a very strong consideration for comercial ventures), in order to grow good quality grapes the choice of what to grow will be decided equally by us to meet our needs and by climate, soil and variety being matched correctly. This will present itself over time.