TruGreen Pesticide Certification Practice Test 2026 (6, 3A, 3B) – Complete Exam Prep

The one-third rule is an important guideline for mowing grass, which states that no more than one-third of the grass blade should be removed during a mowing session. This practice helps promote healthy grass growth and minimizes stress on the plant. Mowing too short can weaken the grass and make it more susceptible to diseases, pests, and environmental stress.

The correct understanding of the one-third rule is that when grass reaches a certain height, it is advisable to mow it back to a specific level that doesn’t exceed the one-third cutting threshold. In this context, mowing when the grass reaches 150% of the desired height means that if the optimal mowing height is, for example, 3 inches, one should mow when it grows to 4.5 inches. This prevents cutting too much of the grass at once, allowing for better recovery and health of the lawn.

The other options suggest mowing strategies that do not align with the principles of effective grass management, either by implying that it is acceptable to cut too short or at inappropriate heights, which could lead to a variety of lawn health issues. Understanding the rationale behind the one-third rule promotes best practices in turf management and ensures a vibrant, healthy lawn.