It wasn’t until I read A Year at North Hill : Four Seasons in a Vermont Garden by Wayne Winterrowd and Joe Eck that I made the connection between the greening of the grass and the frost finally being out of the ground. Grass doesn’t grow in frozen soil, and neither does rain percolate down into the frozen earth. Consequently, when you see the lawn greening up, as it did earlier this week, it is the end of mud season and the true beginning of spring. And yesterday the lawn was mowed for the first time.