By Mary-Jane Pilgrim, Master Gardener

Do you ever wonder what’s going on in the garden when temperatures drop below freezing? How do perennials, shrubs and trees withstand the cold and dehydration of winter?  As we prepare for the colder season above ground, a process of adapting to this change is also going on below ground.

What is Garden Dormancy?

Dormancy is a period of reduced growth in plants, allowing them to survive intense conditions such as cold temperatures or drought. During dormancy:

• Trees and shrubs shed their leaves, reducing water loss and protecting against freezing temperatures.
• Perennials retreat underground, focusing their energy on the roots rather than above-ground growth.

Dormancy is essentially a plant’s version of hibernation. Even though the plant may appear lifeless, it’s very much alive, just in a resting state.

Why Do Plants Go Dormant?

• Survival Mechanism: Dormancy helps plants endure harsh conditions, preventing them from growing in unseasonal warm spells only to be killed by a subsequent freeze. 
• Rest and Rejuvenation: It allows plants to rest, develop stronger root systems and trunks, and accumulate the energy needed for vigorous growth in the spring. 
• Timing and Environmental Cues: Plants respond to environmental cues like shorter day lengths, decreasing temperatures, and reduced light to signal the onset of autumn and the need to prepare for dormancy. 

The Gardener’s Role During Dormancy

• Understanding the Cycle: Gardeners learn to recognize the signs of dormancy and understand its importance for plant health and the overall garden ecosystem. 
• Winter Protection: Proper care during dormancy, such as using mulch or wrapping to protect against frost, helps safeguard plants from potential damage. 
• Be patient: In spring, don’t panic if some perennials take longer to re-emerge. Late risers like perennial hibiscus, Rose of Sharon and some ornamental grasses may take several weeks longer than others to show signs of growth.
• Rest and Relaxation: Just like the plants in their gardens need rest, so too does the gardener. The slower seasons of fall and winter allow us to take stock of our gardens — what worked, what didn’t work, what needs to change — so that we approach next spring and summer rejuvenated!

Resources

Dormancy: A Key to Winter Survival

When Plants Go Dormant: How Hibernating Helps Them Survive

Understanding Plant Dormancy