Hardiness (plants)

– Winter hardiness
– Winter-hardy plants grow during the winter or remain healthy and dormant
– Includes cultivated plants like cabbage, broccoli, and carrots, along with bulbs like tulips
– Many domestic plants have assigned hardiness zones indicating their survival climates
– Winter gardens rely on the cultivation of winter-hardy plants
– Hardy evergreens also fall under this category

– Mechanisms
– Woody plants survive freezing temperatures by preventing ice formation in living cells
– Survival mechanisms include supercooling and dehydrating cells to allow water to freeze
– Plants not acclimated may not survive freezing temperatures
– Some woody plants can survive down to -40°C using these mechanisms
– Understanding these mechanisms is crucial for plant survival in harsh climates

– Hardiness ratings
– Various systems are used globally to rate plant hardiness
– The USDA hardiness zones in the US are based on average minimum yearly temperatures
– The Sunset Climate Zone system is more specific to climates and less dependent on yearly minimums
– The UK has a narrower range of temperatures due to the Gulf Stream, affecting plant hardiness
– Plant hardiness can also be influenced by stress levels and sudden changes in winter weather

– Other hardiness
– Heat tolerance is often considered alongside cold-hardiness, especially in the US Heat Zones
– Drought tolerance and flood tolerance are crucial factors in plant survival
– Wind tolerance mechanisms are still not fully understood
– Wind can cause mechanical stress, cold, and dryness in plants
– Plants may adapt to wind by changing size and responding physiologically to mechanical forces

– See also
– Microclimate is an important factor influencing plant hardiness and survival