Certified Professional Horticulturist (CPH) Practice Exam

When is the best time to water your lawn?

1. Early morning

2. Early evening

3. Midday

4. Dusk

The correct answer is: Early morning

Watering your lawn in the early morning is considered the best practice for several reasons. During this time, temperatures are cooler, which reduces evaporation rates and allows more water to penetrate the soil and reach the roots of the grass. Additionally, watering in the early morning helps the grass dry out during the day, minimizing the risk of fungal diseases that thrive in damp conditions. Watering in the early evening can lead to higher humidity and longer periods of moisture on the grass blades overnight, promoting disease in warm, moist conditions. Midday watering is generally ineffective, as the heat causes much of the water to evaporate before it can be absorbed by the soil. Lastly, watering at dusk can also create a similar issue to early evening, as the grass may remain damp through the night, increasing the potential for disease. Therefore, early morning is the most effective time for watering a lawn, striking a balance between moisture and promoting healthy grass growth.