Certified Professional Horticulturist (CPH) Practice Exam

What is the function of mulching in gardening?

1. To enhance the aesthetic appeal

2. To conserve moisture

3. To directly provide plant nutrients

4. To repel pests

The correct answer is: To conserve moisture

Mulching serves several important functions in gardening, with one of its primary roles being to conserve moisture in the soil. When mulch is applied, it creates a barrier on the soil surface that reduces evaporation. This means that less water is lost to the atmosphere, making it more available for plants. This is especially beneficial during hot, dry weather conditions, as it helps maintain a more stable soil moisture level, which promotes healthy plant growth. In addition to moisture conservation, mulch can also provide temperature regulation by keeping the soil cooler in the summer and warmer in the winter. It helps to suppress weeds by blocking sunlight, which can compete with plants for resources. Mulch can also improve soil health over time as organic materials decompose, eventually adding organic matter back into the soil. While mulching can enhance the aesthetic appeal of garden beds and may contribute indirectly to pest management by covering the soil, its chief function centered in the context of this question is indeed moisture conservation.