Surviving winter - how perennial plants thrive in the cold

By Scout Nelson

Winter casts a quiet sleep over gardens, with snow covering the earth and cold air halting growth. But below the ground, perennial plants are resting, ready for spring to roll out their colors again. How do these resilient plants manage to survive the cold and bloom with each warming?

Hardy Perennials - Underground Warriors

Even as their aboveground foliage succumbs to winter's bite, the roots of perennial plants stay shielded beneath the earth. The ground provides a natural insulator, keeping plant crowns snug and significantly warmer than the frigid air above. When temperatures rise, these resilient survivors burst through the soil, ready to grow and greet the sun.

Snow - A Natural Blanket

Snow is a boon for perennials, acting as a protective layer that locks in soil warmth. A lack of snow cover can be harmful, exposing the dormant crowns to deadly chills. Gardeners often use leaves or keep dead plant matter in place to trap snow, safeguarding the precious life below.

Avoiding "Wet Feet"

A perennial's battle for survival isn't just against the cold but also against the wet. Plants like Delphinium and Echinacea are prone to rot if the fall is wet and soils fail to drain. Good drainage is crucial, making heavy, clay-rich soils a potential hazard for wintering plants.

The USDA Hardiness Zone Map - A Guiding but Imperfect Tool

Selecting plants based on the USDA Hardiness Zone Map is common practice, yet it's not foolproof. Despite choosing zone-appropriate varieties, extreme temperatures can exceed historical averages, challenging plant resilience. Zones 3b, 4a, and 4b in North Dakota bear the brunt of these temperature dips, underscoring the map's limitations as a predictor.

Shrubs: The Aboveground Battlers

Ornamental shrubs face their own set of winter woes, with exposed branches braving the cold without the snow's insulating touch. Spring's unpredictable forays into warmth can coax out new growth, which is then vulnerable to sudden frosts.

Admiring the Tenacity of Flora

It's a testament to nature's endurance that plants can survive such extremes. With gardeners' help and the development of robust new varieties by plant breeders, the northern landscape continues to be a place of beauty and vitality.