Why Great Grapes Grow in the Wisconsin Ledge
(Condensed from wine-searcher.com)
Wisconsin Ledge is an American Viticultural Area (AVA) on the edge of Lake Michigan in Wisconsin covering 3,800 square miles. The climate is heavily moderated by the proximity of several large bodies of water, and French-American hybrid grape varieties such as Frontenac, Niagara and Marechal Foch do best in this cool-climate region.
The topography of Wisconsin Ledge is the result of ancient glacial movement. The land on the peninsula slopes gently upward from the shores of Lake Michigan to the top of the Ledge, before dropping sharply off into Green Bay. Most of the vineyards lie on these eastern-facing slopes that benefit from constant air movement from Lake Michigan, which stores warmth during the summer. The presence of the lake produces a vacuum of sorts during the growing season: warm air over the lake rises, sucking colder air off the land and creating offshore breezes. Cold air cannot settle over the vineyards and there is a constant flow of warmer air, making the growing season here longer than in other parts of Wisconsin.
Wisconsin Ledge's glacial soils are made up of gravel, sand and clay over limestone bedrock. These are well drained, with poor fertility, making them excellent for growing grapes. A lack of water in the ground leads to vines with lower yields and vigor, resulting in the production of high-quality grapes. An aquifer below the AVA provides mineral-rich groundwater to the vines, encouraging deep root growth. This aquifer maintains a consistent temperature, which warms the ground in early spring and late fall, causing fog that helps to protect vineyards from devastating frosts.
The topography of Wisconsin Ledge is the result of ancient glacial movement. The land on the peninsula slopes gently upward from the shores of Lake Michigan to the top of the Ledge, before dropping sharply off into Green Bay. Most of the vineyards lie on these eastern-facing slopes that benefit from constant air movement from Lake Michigan, which stores warmth during the summer. The presence of the lake produces a vacuum of sorts during the growing season: warm air over the lake rises, sucking colder air off the land and creating offshore breezes. Cold air cannot settle over the vineyards and there is a constant flow of warmer air, making the growing season here longer than in other parts of Wisconsin.
Wisconsin Ledge's glacial soils are made up of gravel, sand and clay over limestone bedrock. These are well drained, with poor fertility, making them excellent for growing grapes. A lack of water in the ground leads to vines with lower yields and vigor, resulting in the production of high-quality grapes. An aquifer below the AVA provides mineral-rich groundwater to the vines, encouraging deep root growth. This aquifer maintains a consistent temperature, which warms the ground in early spring and late fall, causing fog that helps to protect vineyards from devastating frosts.
