Certified Professional Horticulturist (CPH) Practice Exam

What is a common indicator of soil health in horticulture?

1. Number of weeds present

2. Color of plants

3. Soil pH level

4. Presence of insects

The correct answer is: Soil pH level

Soil pH level is a fundamental indicator of soil health in horticulture because it significantly influences nutrient availability and microbial activity within the soil. Different plants have varying pH preferences, and maintaining the appropriate pH is essential for optimal growth and development. A pH that is too high or too low can lead to nutrient deficiencies or toxicities, adversely affecting plant health. Understanding soil pH allows horticulturists to make informed decisions regarding soil amendments, fertilization practices, and plant selection. Regular monitoring of soil pH can help ensure the right conditions are maintained for healthy plant growth and effective soil management. While the number of weeds present, the color of plants, and the presence of insects might provide some insights into the overall health of a garden or landscape, they are not direct indicators of soil health. Weeds can thrive in various soil conditions, and plant color can be influenced by multiple factors beyond soil pH, including water availability and disease. Similarly, insect presence can indicate pest pressures or ecological balance but does not specifically reflect soil health.