Red Seal Landscape Horticulturist Practice Exam

What does hardening off seedlings involve?

1. Increasing their exposure to sunlight

2. Gradually acclimating seedlings to outdoor conditions

3. Providing constant water until transplanted

4. Fertilizing them before planting

The correct answer is: Gradually acclimating seedlings to outdoor conditions

Hardening off seedlings involves gradually acclimating them to outdoor conditions. This process is essential for ensuring that seedlings transition successfully from a controlled indoor environment, where they often receive optimal temperatures, light, and humidity, to the more variable conditions of the outdoors. During hardening off, seedlings might be exposed to reduced light levels, fluctuating temperatures, and outdoor winds, allowing them to strengthen their stems and develop resilience to stressors they’ll encounter once planted in their final location. This step minimizes transplant shock and increases the chances of survival and growth once the seedlings are planted in the garden or landscape. The other options focus on different aspects of plant care that do not directly relate to the process of acclimation. For example, while increasing exposure to sunlight can be part of hardening off, it is not the complete picture, since this process also involves adjusting to wind and temperature changes. Constant watering is important for seedling health but does not specifically relate to the hardening process. Fertilizing before planting can assist with growth but is not necessary for the hardening off process itself, which is primarily concerned with acclimatization to the environment.