Maryland Pesticide Applicator Category 3 Practice Test 2026 – Complete Exam Prep for Ornamental and Turf

Fertilizer should be timed so the turf can actually take it up and it won’t be lost to the environment. When the ground is frozen or snow-covered, the soil can’t absorb nutrients, so fertilizer tends to sit on the surface and can runoff or be washed away when thawing occurs. If the air temperature is below 40°F, the grass is dormant and nutrient uptake is minimal, so applying fertilizer isn’t effective and increases the risk of losses once temperatures rise or soils dry out. This combination is why Maryland guidelines specify not applying fertilizer under those conditions.

Windy conditions raise drift risk, and applying during rain increases runoff, so those are practical cautions too, but the most direct regulatory restriction focused on preventing waste and environmental loss is the winter conditions described.