We installed a temporary skating rink with a white poly liner early in the winter. Today we drained the water and removed the plastic to find that the grass beneath was bright green. The rest of the lawn is brown as is typical for this time of year. The plastic obviously protected the grass somehow, but can anyone fill me in on the exact reasons?
If you are in a place that's so consistently cold that it occurs to you to set up a backyard skating rink that means it gets really cold throughout the winter. What the ice and plastic has done is insulated the grass below from the wind and colder temperature. It may seem counter intuitive but the ice was actually helping keep the cold wind from lowering the temperature of the ground, so that the grass could survive the winter better and come out of hibernation faster.