Does This Winter Signal The Rebirth of Hybrid Grapes?

Duke Elsner and Paolo Sabbatini of Michigan State University (MSU) published the results of recent bud sampling at the Northwest Michigan Horticultural Research Center in Leelanau County.

Considering the lowest temperature in the Traverse City area was -20F  on March 3rd, the results are positive.

Among the vines sampled, the majority of Riesling and Chardonnay primary buds survived. Pinot Noir and Cab Franc did not fare as well, losing over half their primary buds. However, secondary bud survival rates were “decent” and the MSU report is optimistic about the 2014 crop for these varietals.

For Pinot Blanc and Gruner Veltliner the prognosis is grim “Up North.”  These two varieties were so badly damaged by the polar vortex that this year’s vintage will be minimal.  On the other hand, “several hybrid varieties showed greater than 80% survival of primary buds,” according to MSU.

In coming years, it will be interesting to see if Great Lakes grape growers shift towards hybrids. The rapid growth and recognition of the Northern Michigan and Ohio wine industries has been built on vinifera grapes, not cold hardy hybrids. Hybrid grapes are easier to grow, but consumers have been slow to accept wines made from these new cultivars.

It’s also interesting to compare freeze damage reports from the Lake Erie growing region and Northern Michigan.  While the lowest temperature in Northeast Ohio was – 14F , versus -20F in Traverse City and the Old Mission Peninsula, the vinifera damage in Ohio is reportedly much worse.  Ashtabula County extension agent David Marrison reported in the Ashtabula Star Beacon that Chardonnay and Riesling “had all their buds killed.”  (This story is on the MWP homepage.)

There are a number of possible reasons for the disparity in damage between Northern Michigan and Northern Ohio.  Although it was colder in Northern Michigan, the coldest temperatures in Northern Michigan occurred later in the winter because Lake Michigan is deeper than Lake Erie and did not freeze as quickly.  Michigan vines therefore had more time to become fully dormant before the worst of the cold hit.

The Traverse City region also had more snow cover than the Lake Erie growing regions.  But the snow in Northern Michigan was not deep enough to cover most of the tender grape buds, so it did little to protect them.  Yet more buds apparently survived in Northern Michigan than around Lake Erie.

A recent statement from a major Ohio wine organization reassured grape growers and consumers that this winter is a “once in a  lifetime incident.”  If you are under 40 years old, this may seem like a true statement.

But if you’re a baby boomer or older, you will remember some bone chilling winters. Although now a distant memory, a string of bitter winters in the late ’70’s is a reminder that occasional arctic weather is part of life in the Midwest.  

Constant reports of global warming and almost 20 years of relatively warm winters convinced many Midwesterners that winters in our region had moderated.  When the USDA shifted the grow zone map north a few years ago, it was seen as official confirmation that nature had become kinder and gentler. But this winter proved that it still gets very cold around 45 degrees latitude in the center of North America.

While the media debates the effect of humans on the weather, fruit farmers are left to grapple with the harsh realities. Fortunately for mankind, the adaptability and resilience of the people who grow our food (and wine) is remarkable.  

How grape growers respond to this winter will have lasting implications for the Midwest wine industry. Will there be a shift towards cold hardy wine grapes in the Midwest?  Only time will tell, but cold hardy hybrids might be what we can grow best in the Midwest.

 See: Harsh Winter for Wine Grape Buds