Spring cleanup: mid-April to early May
Once the snow has melted and the ground is no longer soft, the lawn needs air and light. Leaving matted grass, sand and leaves in place keeps the soil wet and cold, and that is where snow mould spreads.
Working a lawn while it is still waterlogged damages it, so we wait for the soil to firm up before the spring cleanup. In most years that is the second half of April.
