...In Michigan, the $40 million annual crop is also at risk, reports theGreat Lakes Echo of the Knight Center for Environmental Journalism at Michigan State University. Christmas trees, traditionally grown in poor soil, have always been at the mercy of weather -- of all kinds. Wisconsin's Miller explained that even those few trees that survived the summer are at risk. A deep frost isolates a sapling's roots from moisture, he said, explaining he hopes a large snow pack will insulate the ground from extreme temperatures. However, Miller said, even if an early spring arrives, “We’ll probably lose more over the winter.” (Read more)