OVER THIRTY YEARS ago, I moved into a 19th-century farmhouse shortly before snow started falling, burying whatever remained of the previous owner’s garden. I patrolled the yard daily once the snow melted, and among the earliest sprouts were points of green that I initially thought were hyacinths. As they emerged further, the leaves became wider and I guessed they were tulips. As they grew to their final height, over a foot (30 cm) tall and six inches (15 cm) wide, with no sign of flowers I had to admit I didn’t know what they were.