At this time of year we are subject to heavy frosts in unusual places. If the temperature is below freezing, there is a good chance frost will be present somewhere. Do not drive, walk or work on the grass when temperatures are below freezing! And here’s why:
Grass blades are exquisitely beautiful when covered with frost. There is something magical about a hoary frost in the early morning light which conjures picturesque images of Jack Frost and the winter to come. However, do not be fooled by the fairy tale. Far from benign, frost is essentially miniature frozen daggers arranged randomly all over the turfgrass blades. When you walk or drive on frosted grass, the pressure of your foot or tire forces these tiny ice daggers into the grass blade. Nobody wants to get stabbed by millions of tiny ice daggers, least of all turfgrass blades. When this injury happens, the grass blades first turn black, then brown as they die a tortuous death. Additionally, turf damage done at this time of year is particularly devastating because the grass blades have stopped growing for the season. Turfgrass damaged in the fall or winter will not recover until next spring. Any damage that occurs now will be a constant reminder throughout the entire winter of your senseless disregard for the health and well-being of turfgrasses everywhere.
The tricky thing, however, is that just because there is no frost visible does not mean there is no frost present. A light frost or a frost at soil level will not necessarily show itself. Sometimes, even a heavy frost will melt off the outer turfgrass canopy but still be present on the interior canopy long after air temperatures have risen above freezing.
So, in the humble opinion of an expert horticulturalist, your best course of action is as follows:
1) Never drive on the grass in the winter.
2) Never walk on frosted grass.
3) Stay on the paved paths.
For the sake of your turf, it is better to enjoy the frosted beauty of winter from your cozy chair by the window, as you sip your cocoa, pour over garden catalogs and dream of mows to come.