The question of whether to cut your grass when the ground is dry is a common dilemma for homeowners. Mowing should be determined not by the calendar, but by the current physiological condition of the grass. Cutting a struggling lawn can inflict long-term damage, but adjusting your technique for mildly stressed grass can help it survive the dry period. A brief visual inspection determines the best course of action to maintain turf health until the next rainfall.
Recognizing Stress and Dormancy
Understanding the difference between mild drought stress and full dormancy is the first step in protecting your lawn during a dry spell. The most reliable diagnostic tool is the “footprint test,” which assesses the turgidity, or internal water pressure, of the grass blades. If you walk across the lawn and your footprints remain visible for more than a few minutes, the grass lacks the water pressure to spring back and is experiencing significant stress.
The color of the grass also signals its level of distress. A healthy, deep green color may transition to a blue-green, grayish, or purplish tinge when the plant begins to dehydrate. When the grass progresses to a uniform tan or straw-brown color, it has likely entered drought-induced dormancy. Dormancy is a natural survival mechanism where the plant shuts down top growth to conserve energy and water in the root system. If the lawn is completely brown and dormant, all mowing activity must cease.
Mowing Height and Frequency Adjustments
If your lawn shows only mild stress or a slight color change, and a cut is necessary, you must make immediate adjustments to your mowing routine. Raise your cutting deck to its highest setting, aiming for a final grass height of at least three to four inches. Taller grass blades shade the soil surface, which helps to keep the ground cooler and significantly reduces the evaporation of moisture from the soil.
Adhere strictly to the “one-third rule,” which states you should never remove more than one-third of the grass blade’s total height in a single session. For example, if the grass is four inches tall, only remove about 1.3 inches. This rule minimizes shock to the stressed plant. You should also reduce mowing frequency, potentially skipping a week or two, since growth naturally slows during dry conditions.
Ensure the mower blades are sharp, as dull blades tear the grass, creating wounds that allow the plant to lose moisture and increase vulnerability to disease. The best time to mow a mildly stressed lawn is during the cooler part of the day, such as the late afternoon or early evening. Mowing during midday heat adds unnecessary stress to the struggling plant. Leaving the clippings on the lawn, known as grass cycling, acts as a natural mulch that helps retain soil moisture.
Why Cutting Highly Stressed Grass Causes Harm
Cutting a severely stressed or fully dormant lawn carries significant risks for the grass plant. Grass blades are the primary site for photosynthesis, the process by which the plant generates the sugars needed for energy and growth. When a significant portion of the leaf tissue is removed during a drought, the plant loses its main energy source.
To recover, the stressed grass must divert stored energy reserves from its root system to regrow the missing leaf tissue. This depletion is detrimental because the roots are already conserving resources to survive the lack of water. Cutting also creates open wounds that can increase the plant’s susceptibility to pathogens, disease, and insect damage. Cutting a fully dormant lawn risks scalping the crown—the point where the leaves and roots meet—which can permanently damage or kill the plant.