Late-October marks the return to watching overnight lows like a hawk. We had our first frost last weekend, but we were more or less prepared. Lisa, Michael, and I spent Friday morning harvesting greens and peppers for the Saturday pickup, and in the afternoon, we shifted the last of the sweet potatoes to the safety of “The Cube,” an insulated, unplugged walk-in that serves as our root cellar. At 7am Saturday morning, I drove out to the fields to check on the arugula and brocc