Itasca Joins List of Cold-Hardy Grapes

University of Minnesota names new variety for white wine production

by Linda Jones McKee
u.s. plant cold hardiness map
The white wine grape Itasca is recommended for Zone 4 areas identified on the USDA's Plant Hardiness Map.
Minneapolis, Minn.—A new white wine grape variety will soon be available for nurseries scrambling to meet the growing demand for vines able to thrive in northern parts of the United States and Canada. Dr. Matthew Clark, assistant professor of grape breeding and enology at the University of Minnesota, on April 4 announced the name of the fifth new variety created by the school’s breeding program: Itasca.

Peter Hemstad, formerly the university’s grape breeder and viticulturist, named four grapes released by the program, beginning in 1995 with Frontenac, a red grape, which was followed by two white grapes, La Crescent in 2002 and Frontenac Gris in 2003, and another red, Marquette, in 2006.

Independent breeders including Tom Plocher of Hugo, Minn., have introduced several cold-hardy red varieties—Petite Pearl in 2009, Crimson Pearl and Verona in 2015— but a cold-hardy white grape that had the fruit chemistry to allow winemakers to produce a good dry white wine had not been released. Clark told Wines & Vines he thinks Itasca is cold hardy, disease resistant and can produce “wine quality that is fantastic.”

Identified in 2009 as MN 1285, Itasca was the result of a 2002 cross, made by Hemstad and his group, of Frontenac Gris and MN 1234, which has Seyval in its background and is known for its resistance to powdery mildew. The vines have an upright growth habit and do well on either a VSP or a high-cordon trellis, although on a high-wire trellis some leaf pulling may be necessary. According to Clark, spring is short in Minnesota, and Itasca vines respond accordingly: They can go from bud break to flowering in one week. Because of the vines’ vigor, Clark recommends up to 8 feet spacing between vines, depending on the soil in the particular vineyard.

On the most critical factor of survival over Minnesota’s harsh winters, Clark noted, “Itasca’s hardiness level is superb. In 2014, the winter of the Polar Vortex, Frontenac had 25% to 27% primary bud survival, while there was 65% primary bud survival in Itasca. We’re recommending it for Zone 4 (on the U.S. Department of Agriculture’s plant hardiness zones map), mostly because the frost-free days in Zone 3 are too few to ripen the grapes.”

Itasca in the research vineyard has been harvested in the past two weeks in September. Its moderately compact clusters are resistant to powdery mildew, a trait inherited from Seyval, and also to downy mildew and Phylloxera. Clark commented that when the grapes are ripe, the clusters take on a golden hue, and then “one berry in the cluster turns pink; it’s a sign the cluster is ripe and it’s time to pick.” Depending on the harvest date, the sugars can range from 24° to 28° Brix, with a pH of 3.17 and a TA of 10 g/L, which compares with 15 g/L for Frontenac Gris. The average cluster weight is 145 grams, while Frontenac grape clusters average 124 grams.

The grape chemistry of Itasca “give a lot of opportunity for winemakers to make different styles of wine, and favor a dry style,” Clark said. The berries have flavors of melon, pear and star fruit that translate into the ultimate wine, which can also have notes of honey, quince and minerality.

All of the grape varieties from the breeding program at the University of Minnesota have names that are related to Minnesota places. Itasca is the name of the state park in northern Minnesota that surrounds the headwaters of the Mississippi River; Frontenac is a state park along the Lake Pepin area of the Mississippi River in southeastern Minnesota; La Crescent is a town that takes its name from the bend (or crescent shape) of the Mississippi River as it flows around the town; and Marquette was the French missionary and explorer (Jacques Marquette) who mapped the northern portion of the Mississippi River in the mid-1600s.

Several nurseries have been preparing for the launch of Itasca and should have grapevines available for planting in 2017, including Double A Vineyard, Fredonia, N.Y.; Winterhaven Vineyard and Nursery, Janesville, Minn.; and Northeast Vine Supply in West Pawlet, Vt.

Posted on 02.03.2018 - 08:29:33 PST
I am a small home grower of wine grapes. I have ordered 15 plants of Itasca. I also am getting 5 LA Crescent also another Minn. grape. My zone is 5 so I am hoping for good results.