The soils in our Tassel Ridge Vineyard at the Winery are a mix of loess and loam with pockets of clay. Loess is a sandy windblown soil that drains well and when combined with the loam, we have well-drained, rich soils.
The loess soils blew in from the bend in the Des Moines River downstream from the dam and slightly north of where it now flows under State Highway 92. About 10,000 years ago, the seasonal swing in temperatures was more severe than it is now. In the winter, the cold temperatures meant that the river was frequently low and usually frozen. The banks were wide and they were full of fine sand. High wines out of the west would blow the sand to the east and some of it was stopped by what we now call Tassel Ridge. In the summer, temperatures were much higher and the melting Des Moines lobe of the glacier would keep both the Des Moines and Racoon Rivers flowing at full capacity. They would move a lot of sand downstream. The glacier eventually melted and the seasonal flows of water moderated.
Today, our vineyard contains this loess sand as well as loam. It is an excellent combination for grape growing.
