Plocher-Vines, a leader in breeding new cold hardy grapes.

A long and winding road
Tom has been breeding grapes in Hugo, Minnesota since 1996. But his interest in grapes and wine goes back to 1978. Tom was working in Germany during the autumn of 1978 and spent weekends touring the wineries and vineyards of the Mosel River Valley. It was a major life event. He came back to Minnesota and planted Cayuga White grapevines in 1979 and learned to make wine. He met renowned Wisconsin grape breeder Elmer Swenson and knew immediately that he was the guy to learn from. Elmer became Tom’s mentor and friend.

Know your parents
One lesson from Elmer was to deeply understand the varieties you are using for parents. Between 1980 and 1996, Tom grew over 100 grape varieties-French Hybrids, U of Minnesota selections, Elmer Swenson and David Macgregor selections. Tom evaluated these in the vineyard. He also produced and evaluated wine samples from almost all of them. Together with his colleague, winemaker Gordon Rouse, he conducted controlled freezing tests on dormant buds from a host of grape selections. From these experiments, he selected the cultivars that he would use as “super-hardy parents” in his crosses. A series of nasty 40 below zero winters validated the controlled freezing results. From the many wine samples he produced, Tom identified the cultivars he would use as “quality parents” in his crosses. These ten years of experimentation with many different grape varieties set the stage for the first crosses in 1996 and 1997, which would lead to Petite Pearl, Crimson Pearl, Verona and T.P. 1-1-12.

A Broad Genetic Base
Another lesson Tom learned from Elmer was the value of casting a wide net and combining diverse breeding lines in crossings. Tom’s “super-hardy parents” come from three distinctly different lines of breeding: E.S. 10-18-06 and E.S. 10-18-14 from Elmer Swenson, MN 1094 from the University of Minnesota, and Riparia x St. Croix #5 and DM 8521-1 from David Macgregor. His “quality parents” have come primarily from Elmer Swenson's work. But he also has relationships with the Julius Kuhn Institute-Geweilerhof, Germany, UC-Davis, the National Clonal Germplasm Repository at Geneva, NY, and private grape breeders in Norway, Latvia, and China. All have been generous in providing Tom with pollen of valuable and often rare grape varieties to use as quality parents. Among the native species used in Tom’s recent crosses are Vitis palmata and Vitis cinerea, intended to promote the traits of slow spring growth and disease resistance in their progeny.

A Background in Research and Development
As a Psychobiology graduate student at Yale back in the 1970’s, Tom acquired his skills in observation, measurement, research design, and analysis. Skills that still serve him well in his grape breeding work. From Yale, he went on to a long career as a staff scientist at a technology industry corporate research and development laboratory. His product development experience there shaped how he goes about his grape breeding work, driven by the needs of grape and wine producers and with specific goals and milestones to guide his grape breeding projects.

Tom Plocher hand-pollinating at bloom time

Spectrophotometer measuring grape tannin

Click for a timeline and history of Tom’s grape breeding work.