Shiitake mushrooms require faith in the unseen. The fungi flourish under the cover of bark for nine to twelve months preceding the first harvest, during which eternity you can do little more than cross your fingers. Once established, though, the crop will produce fruit for approximately seven years. Plus, these umami bombs fetch as much as $20 per pound at farmers markets. Up for the challenge? You’ll want to get started now, harvesting the logs that will serve as your growing medium before trees bud out and release the nutrients stored in their sapwood.