During the winter I am often asked if a layer of snow will harm the grass. The basic answer is no, it will not harm grass at all. In England, your cool-season grass will be happy and content even under a thick blanket.
In England we grow cool season grasses, which are quite at home in mild temperatures of a British winter.
The environmental conditions underneath snow are quite stable. Plants are tucked in out of the way of any cold, drying winds. The temperature between the ground and the snow is a lot warmer than above and it stays quite constant. Usually just above zero degrees Celsius. Grass is fully hardy and can withstand even the coldest UK temperatures.
Here in the the north west of England we rarely receive prolonged snow fall or a settled covering for more than a week or so. Extreme, prolonged cold like that in experienced in North America and Canada are very rare in Britain.
Grass can live happily under snow
Grass can stay alive happily because sunlight can also still get through to the leaves. This allows the plant to continue to make food through photosynthesis. Once the snow melts the grass can sometimes look greener than before.
Snow settling around the plants and does not compact it or damage the leaves. Even when a considerable amount falls it is a gentle, even pressure which the grass can withstand. Problems can arise when you stand on this snow and compact it into the grass.
Kids love to make a snowman in their garden from fresh snowfall. This activity can cause a bit of a problem for the grass below. Stepping on the ice compacts it down and can damage the leaves of the grass. When under pressure, frozen water inside the leaves cause damage to the cell walls. This causes the upper part of the leaf to turn brown and die. If this happens, when the snow melts you may see footprints of damaged on the grass.
Don’t worry too much. It is only light damage and it will grow out as soon as the temperature warms.
You can get problems with fungal diseases infecting grass under snow. The damp, high-carbon dioxide environment on the soil surface is a haven for pathogens. Problems like snow mould (fusarium patch disease) can spread unseen.