What does "hardened off" refer to in plant care?

The term "hardened off" refers to the process of acclimating indoor plants to outdoor conditions. This is essential for plants that have been grown indoors or in a protected environment, as they may not be accustomed to the harsher conditions such as direct sunlight, wind, and temperature fluctuations found outdoors.

To properly harden off plants, gardeners typically begin the acclimatization process gradually, exposing the plants to outdoor conditions for increasing amounts of time over several days to a couple of weeks. This helps them adjust to the new environment, reduces transplant shock, and increases their chances of survival once planted outside.

This practice is crucial for the successful transition of plants from an indoor setting to the outdoor landscape, ensuring they are robust enough to thrive in their new environment.