From our perspective as plants, dormancy is not a state of sleep but a strategic retreat. It is a deeply ingrained survival mechanism passed down through generations to endure periods of environmental stress, primarily extreme temperatures or severe drought. When conditions become unfavorable for active growth, we significantly slow down our metabolic processes. This conservation of energy and resources is crucial. During dormancy, our focus shifts from producing new leaves or stems to simply maintaining core cellular functions and preserving stored water. Attempting to grow when temperatures are scorching or freezing would be a catastrophic waste of precious water and energy, likely leading to our demise. Therefore, dormancy is our way of waiting patiently for the return of conditions that favor successful growth and reproduction.
For those of us classified as winter growers, our active growth period occurs during the cooler, often wetter months of autumn, winter, and spring. Our dormancy coincides with the hot, dry summer. The intense summer sun and high temperatures pose a dual threat: they dramatically increase the rate of water loss through our leaves (transpiration) and can literally cook our sensitive root systems in the soil. To survive, we enter a state of summer dormancy. You will notice that we virtually stop producing new growth. Our outer leaves may even appear a bit shriveled or dry as we reabsorb moisture from them to sustain our core. Watering us heavily during this time is dangerous, as our roots are largely inactive and unable to absorb the moisture, leaving them susceptible to rot. We are merely resting, biding our time until the cooler autumn rains signal that it is safe to "wake up" and begin our growth cycle anew.
Conversely, for us summer growers, our active period is the warm summer months. We thrive in the heat and sunlight, using this energy to fuel rapid growth, flowering, and storage. However, we are highly susceptible to cold. When temperatures drop significantly, the water stored within our tissues can freeze, forming ice crystals that rupture our cell walls and cause fatal damage. To avoid this, we enter a state of winter dormancy. As daylight hours shorten and temperatures fall, our growth grinds to a halt. We channel our energy inward, fortifying our cells with sugars and other compounds that act as a natural antifreeze. During this time, we require very little water, as cold, wet soil combined with our inactive roots is a perfect recipe for rot. We remain in this suspended state until the warmth of spring assures us that the risk of frost has passed.
The shift into dormancy involves profound internal changes. Our respiration rate—the process of burning sugars for energy—slows dramatically to conserve carbohydrate reserves. Photosynthesis also decreases significantly because producing new chlorophyll and supporting high metabolic activity is inefficient under stress. Root activity diminishes almost entirely; the fine, hair-like roots responsible for water uptake may even die back to be regenerated when the growth season returns. Our focus becomes maintenance, not expansion. Hormonal balances shift, with growth-promoting hormones like auxins and gibberellins declining, while abscisic acid, a hormone that promotes drought tolerance and seed dormancy, increases. These changes are not a sign of ill health but are a clear indication of a highly adapted plant successfully navigating a harsh season.
