Normally scalping your lawn is considered a dangerous practice worthy of chastising from your neighbors and kids. When done often, it can cause severe damage and maybe even kill your grass.
What is scalping then, exactly?
Scalping is like giving your lawn a haircut that is too close to the scalp. When the grass is cut too short, it takes off too much of the green blade, exposing the stem closer to the ground. Without the blade, the grass can’t take in sunlight and other needed resources. This then results in brown patches across the lawn.
But! Like with so many other aspects of landscaping and caring for your turf, it isn’t always bad. In some cases—especially if you grow Bermudagrass—scalping has a valuable purpose and is encouraged.
I’m sure you’re wondering how this contradiction works.
Bermudagrass develops a thick layer of thatch over time. When left to its own devices, this thatch smothers new grass shoots, robs moisture from the soil, and even harbors nasty plant diseases. Scalping Bermudagrass, in turn, reduces this thatch, helping you get the most out of your lawn while preventing grass disease and death.
By cutting Bermudagrass incredibly short and removing the thatch, the soil is exposed to more sunlight. This results in increased soil warmth that helps boost root development and encourages better grass growth.
Unlike other grasses, Bermudagrass often grows back after scalping because it grows via above-ground stolons and underground rhizomes. If the scalping does cause tissue damage to the lateral stolons, the underground shoots can produce new grass blades.
If you are going to scalp your Bermudagrass, it’s essential to know when to scalp:
Scalp in the spring to remove thatch build-up and dead grass to promote a faster spring green-up, thicker growth, and an overall healthier lawn. Time to so you scalp after the frost danger has passed and the soil temperature is above 60°F. You want to do it just as the grass starts to green, but before the entire lawn is green.
Scalp in the fall to remove thatch if you are overseeding with cool-season grasses like fescue or ryegrasses. Removing the thatch allows more cool-season seeds to reach the topsoil, promoting a greener winter lawn.
Keep in mind, though:
Never scalp your Bermudagrass in early spring if there is still a chance of frost. Newly scalped turf is incredibly susceptible to frost damage.
If you do scalp right before winter, it may weaken it, making it more vulnerable to winter conditions. Scalp in early to mid-fall to give the grass time to recover before the cold weather comes.
When Do You Scalp Bermuda Lawns & When Is It Too Late
Scalping of a Bermuda lawn is an effective tool in fostering growth. Typically scalping is accomplished by cutting grass to a length of half an inch (about one centimeter). Doing so has several benefits to the lawn.
Shorter grass exposes more of the soil to the sun, allowing it to warm up faster. A scalped yard will also remove much of the past seasons dead growth which could have a suffocating effect. This will promote both disease and weed growth in the yard.
Scalping allows for new growth to come in stronger and healthier, making a yard greener, thicker and more weed resistant.
It is important to scalp a Bermuda lawn at the right time.
Scalping should only ever be done when the yard is in dormancy, a state where the grass is neither dead nor green and growing. This occurs in cooler months and the grass will turn brown but the roots will still be alive and holding soil.
If clumps of grass are able to be pulled up by hand, the yard is not dormant but dead. It is important to choose the right time to scalp a yard.
If the lawn is scalped before the last frost any new growth that occurs will die when temperatures dip again.
Typically a good time to scalp in between mid-March and the end of April. The danger of frost has passed and the soil temperature is at an level that promotes new growth (60 degrees Fahrenheit or 15 degrees Celsius).
After the end of April Bermuda grass has left dormancy and is greening up again. At this point it is too late to scalp a lawn. The stress caused by scalping non dormant grass can sometimes kill it, if not it will be susceptible to disease and weed growth.
One scalp prior to growing season is usually sufficient. This allows the grass to recover before it goes back into dormancy. If overseeding a lawn with a cool season grass (such as a fescue), the lawn can be scalped again in the fall once it has gone dormant.
This second scalping should occur once the grass stops growing and soil temperatures have dipped below 60 degree Fahrenheit. The cool weather grass will then be allowed to reach the top soil and begin growing. If not planning on overseeding the stress given to the yard is not worth the return and the second scalping should be skipped.