What happens to grass in winter? Surprisingly, a lot! Some people might think that grass dies in winter, but that's not always the case. So, what exactly is going on with your lawn if it’s not dead? Is it just asleep? Join us as we take a closer look at the workings of a winter lawn!
When temperatures drop and the days get shorter, grass looks like it may have died. In reality, though, most lawns are just going dormant for the winter season. However, certain fungal diseases or other complications can arise during winter dormancy that could potentially cause some grass to die.
Dormancy is triggered by cooler temperatures and less sunlight, which causes grass blades to lose their vibrancy and turn tan or brown. While you may think that your lawn is dead, it will typically bounce back when conditions become more favorable in the springtime.
Lawns start browning in winter because there is no sunlight available for photosynthesis. Because of this, and colder temperatures, the enzymes that allow your lawn to break down nutrients and respirate can not function properly. As nutrients leave the grass blades and get stored in your lawn's root system, your grass will slowly start to lose its green color.
Dormancy serves as an important protective mechanism that helps grass survive during the coldest winter months. By going dormant, your lawn is able to conserve energy until spring when it can begin growing again. When temperatures drop below 40°F for extended periods of time, you should expect your lawn to start to go dormant.
Think of dormancy as your lawn hibernating. Much in the same way many mammals hibernate underground when temperatures get too cold, your lawn is surviving by going dormant above ground. Like hibernating animals pause their normal activity to conserve energy in the frigid temperatures, the grass in your lawn pauses its growth in order to conserve and store nutrients to use for springtime rejuvenation!
Some types of grass are hardy and can grow even when temperatures are cold. Common cool-season varieties will keep growing during warm winter days with temperatures above 55°F, as long as there is enough moisture. However, these types of grass won't be able to survive in temperatures below 40°F. The most popular cold-tolerant grass types are as follows:
It is also worth noting that dormancy varies from species to species and region to region. For instance, cool-season grasses like fescue or bluegrass are more tolerant of colder weather than warm-season varieties like Bermudagrass or zoysiagrass. This means that some grasses may remain green through most of winter in the warmer coastal and southern states.
Seeding a lawn that has just entered dormancy in early fall is actually very beneficial to the health of your lawn. In fact, as the soil in your lawn freezes and warms over the course of the winter season, seeds get worked into the soil more deeply, which can help with the germination process.
Make sure to seed your lawn before consistent freezing temperatures arrive. You want it to be warm enough for the ground not to freeze, but cold enough that all sprouting has ceased. Below are a few more tips on how you can help preserve the health of your lawn:
Perhaps the most important thing to remember about winter dormancy is that it can end at any time temperatures are warm enough. There is no set date on the calendar that your lawn will start growing again, but it will generally be when temperatures are consistently 55°F and above.
This, unfortunately, means that lawns in more temperate climates may start growing and refreezing if there are peaks of warmer days throughout winter. This process can prevent grass seed from germinating, and it can quickly lead to conditions that cause lawn diseases to form, such as snow mold. Make sure to call a local lawn care provider, like Holmes Lawn & Pest, to treat your lawn for any such issues this spring!