Certified Professional Horticulturist (CPH) Practice Exam

What soil amendment is most appropriate for providing increased nutrients to the roots during potting?

1. Perlite to yield looser media

2. Peat moss to help the soil retain moisture

3. Fertilizer or compost to increase nutrients to roots

4. Shredded fir bark to yield a root system that is more drought tolerant

The correct answer is: Fertilizer or compost to increase nutrients to roots

Fertilizer or compost is the most appropriate soil amendment for providing increased nutrients to the roots during potting. When plants are potted, they need an adequate supply of nutrients to support their growth and development. Fertilizers contain essential macro and micronutrients, such as nitrogen, phosphorus, and potassium, which are crucial for plant health. Compost, on the other hand, is organic matter that not only enhances nutrient availability but also improves soil structure and microbial activity, further supporting plant growth. While the other amendments serve specific purposes, they do not directly address the need for nutrient supplementation. For instance, perlite is primarily used to improve aeration and drainage, which is beneficial for root health but does not provide nutrients. Peat moss retains moisture effectively, creating a suitable environment for roots, yet it is low in nutrients by itself. Shredded fir bark helps create a more drought-tolerant root system, enhancing aeration and drainage, but it also lacks the nutrient content necessary for immediate plant nourishment. Thus, integrating fertilizer or compost into the potting mix directly satisfies the plants' nutritional needs, making it the most suitable choice.