Winter kill was extremely prevalent this spring. Several factors contribute to winter kill. The most likely cause of most winterkill this year was last years dry conditions. Although we did get some moisture last fall, it didn’t come any where close to making up for what the ground was missing. Yes, some people had astronomical water bills and still got winter kill, but most people just don’t realize how much of that water burned off before it penetrated any further than two or three inches down, or how tremendously shortchanged we were by Mother Nature we were. Take a parched lawn. Freeze it. Then let 100 centimetres of snow melt over 4 weeks, then ask it to go through a growth spurt. Only the strongest plants are going to survive the ordeal. How fast the snow melts, how many times the meltwater under the snow on your lawn freezes and thaws, whether the lawn faces north or south, all affect the prevalence and severity of winterkill. The most common cause is meltwater that gets trapped on the lawn that has gone through several hard freezes and thaws. Each time the lawn refreezes, the grass plants suffer microfractures, particularly in the roots, as the soil expands, contracts, and heaves. Too much root damage inevitably leaves the plant without a source of food. It appears green at first in the spring, but quickly dies. There is no way to bring it back. The affected areas should be raked thoroughly to remove dead material and thatch. Lay down a light layer of topsoil and rake in a generous amount of seed.