Certified Professional Horticulturist (CPH) Practice Exam

Which growing requirements differ between plants grown in containers in the landscape?

1. Light, temperature, and humidity

2. Fertilizer, light, and climate

3. Temperature, watering, and hardiness zone

4. Fertilizing, watering, and growing media

The correct answer is: Fertilizing, watering, and growing media

Plants grown in containers in the landscape have specific growing requirements that differ notably from those planted directly in the ground. Containerized plants experience unique limitations and advantages, leading to differences in fertilizing, watering, and the type of growing media used. Fertilizing is crucial for container plants because the soil in containers is more limited in nutrients compared to garden soil. Container mediums are often less fertile than the natural soil, necessitating regular fertilization to support healthy growth. Watering is another critical area where container plants differ. They typically require more frequent watering due to the faster evaporation of moisture from the smaller volume of soil. Containers can dry out quickly, leading to a greater risk of drought stress if not monitored closely. The growing media in containers also varies significantly from in-ground planting. Containers often use a soilless mix or potting soil designed to promote drainage and aeration, which is vital to prevent root rot and promote healthy growth. In contrast, garden soil is usually denser and has different drainage properties. These distinctions highlight the unique needs of container-grown plants and underscore the importance of managing fertilization, watering, and the growing medium effectively to ensure their health and vitality.