How and why your weed died over the winter

Winter kill refers to any serious damage or death caused by turf grass turf during the winter months. Its main signs are lawns that remain brown or bare after the lawn has usually returned to healthy green growth in the spring. For the most part, well-manicured lawn grasses are resilient and strong, but winter weather can be adamant in even the best of lawns. It can take months for the dead spots that were killed in the winter to fill up on their own and you may need to re-sow or re-sow the lawn. Winter killing can occur under a variety of conditions.

Cold dehydration

Grasses can survive almost any temperature when covered in snow, as snow acts as an insulator. However, uncovered grasses in very cold conditions will continue to perspire (lose moisture and oxygen) even if the ground is solidly frozen. Frozen roots cannot replace the moisture sucked out by cold, dry winds, and plants can suffer cell death and possibly even crown death.


Wait patiently to see if the grasses get well again. If the damage is minor, individual grass plants can recover, or surrounding grass plants can fill up. If there is extensive damage, you will likely need to re-seed or re-seed dead areas.

Snow mold

When heavy snow falls on ground that is not yet cold, the damp conditions can favor a variety of fungal diseases collectively known as snow mold. In the spring, when the snow melts, you will notice fuzzy or crusty patches of pink or gray in color that cover parts of the lawn. Snow mold usually dies when the sun and wind dry out the lawn, but if the lawn is infected for a long time, the grass can die. Usually, however, the grasses recover gradually.


If the lawn still has dirt from the previous year, rake it up to improve air circulation to the grass. To prevent snow mold, you should de-felt or aerate your lawn regularly to improve air circulation. Some experts advise against fertilizing the lawn late, as nutrients that are not absorbed and are covered by snow when the ground is still warm can promote mold.

Freeze the crown

The lawn crowns can be killed if warm, humid weather is followed by sudden frost. This is most common in late winter and early spring, especially when unexpected frost occurs in warm climates planted with warm season grasses. If the crows, which have ingested a lot of water, suddenly freeze, the expansion can kill the canopy.


Widespread damage requires overseeding or resodding. There isn’t much you can do to prevent the crowns from freezing. If you live in a borderline climate and have suffered frequent crown frosts, consider overseeding with a turf mix for the cooler season.

Fun fact

Annual aeration in autumn opens the root zone of your lawn and encourages new growth. Combined with overseeding, aeration can help the lawn withstand winter conditions.


One very identifiable type of winter killing is caused by voles – tiny rodents that leave narrow, meandering strips of dead grass on the lawn. The dead paths indicate the places where the voles have completely eaten up the base.


Vole trails usually refill as surrounding grasses send out new roots and shoots. If there is extensive damage, you may have to re-sow. To prevent voles, remove dead grass and fallen leaves in the fall, as this material provides shelter for rodents for their winter adventures.Voles can be caught and baited in the same way as mice, although difficult to do in snow cover.