Bermuda grass is a warm-season turf that requires aggressive maintenance to thrive after winter dormancy. Scalping is the practice of mowing the lawn down to the lowest possible height your equipment allows, typically between 0.5 and 1 inch. This intense reduction in height is done once annually in late winter or early spring. The goal is to remove old, dormant material and prepare the lawn for vigorous, uniform growth.
Why Scalping is Necessary for Bermuda Grass
This aggressive cut is a horticultural necessity because it removes the layer of dead, gray winter blades and accumulated organic material known as thatch. Thatch is a dense, fibrous layer that builds up just above the soil surface. If this material is not removed, it acts like a blanket, hindering the lawn’s health.
Excessive thatch prevents water, air, and nutrients from reaching the root system. A thick layer of thatch also creates a moist environment that harbors pests and disease pathogens. Removing the dormant material directly addresses these issues and resets the turf’s growth pattern.
The removal of the winter canopy allows the sun’s energy to penetrate the soil directly. This warming effect leads to a faster and more uniform “green-up” by encouraging the Bermuda grass to break dormancy sooner. Without scalping, new green shoots must fight through the thick, dead material, resulting in a patchy start to the growing season.
Determining the Ideal Timing in Oklahoma
The precise time to scalp Bermuda grass in Oklahoma is dictated by soil temperature, not a specific calendar date, due to the region’s unpredictable weather patterns. The primary biological trigger for Bermuda grass to begin active growth is a consistent soil temperature between 55 and 60 degrees Fahrenheit. This temperature range guides the timing of the scalping operation.
Scalping too early risks damaging the turf because exposed crowns and developing shoots are vulnerable to a late hard frost. Removing the insulating layer before the last expected frost can cause significant setbacks, potentially delaying green-up. Conversely, waiting too long means the grass is already actively growing, and scalping will remove tender new green tissue, stressing the plant.
In Oklahoma, this ideal window often falls between late February and mid-March for southern regions, shifting closer to late March or early April for the northern Panhandle. Homeowners should monitor local soil temperature reports to ensure correct timing. Scalping immediately before the soil hits the 55-degree threshold ensures the lawn is prepped for the first flush of spring growth.
Step-by-Step Scalping Procedure
Before beginning, ensure the mower blades are freshly sharpened to deliver a clean cut, minimizing stress on the dormant grass crowns. A dull blade tears the grass, leaving ragged edges that invite disease. Clear the lawn of any debris, such as sticks or rocks, which could damage the mower.
The goal is to mow at the lowest possible setting, typically resulting in a final height of 0.5 to 1 inch. If the lawn is currently tall or unevenly cut, lower the mower deck gradually over two or three passes. Cutting from a high winter height to the final scalp height in a single pass can overload the mower and leave clumps of material.
The most crucial step is managing the voluminous debris generated by the cut. All clippings and dormant material must be bagged and removed from the lawn area. Mulching the scalping debris back onto the lawn creates a massive, suffocating layer of organic matter that defeats the purpose of the operation.
Immediate Follow-Up Care
Once scalping is complete and debris is removed, the focus shifts to protecting the newly exposed soil and promoting healthy growth. The first action should be applying a pre-emergent herbicide to prevent summer weeds like crabgrass from germinating. This application must be completed before the soil temperature consistently reaches 55 degrees Fahrenheit, which is when crabgrass begins to sprout.
The herbicide forms a chemical barrier at the soil surface, preventing weed seeds from establishing roots as they germinate. This timing, immediately following scalping, is ideal because the low turf height allows the product to contact the soil directly. Initial watering should follow the pre-emergent application to activate the chemical barrier.
The first spring application of fertilizer should be delayed until the Bermuda grass shows definitive signs of active growth, usually referred to as 50% green-up. Applying nitrogen-rich fertilizer too early while the grass is still dormant will only feed the emerging weeds. Wait until the threat of a hard frost has passed and the turf is actively growing, which often coincides with the second or third regular mow of the season.