Winter underground

With the winter solstice behind us, gardeners begin contemplating lengthening days and the first green growth of spring. But while most plants may seem lifeless at this time of year, that is, of course, an illusion.

Until fairly recently, most people, especially those of us from other climates, believed that non-evergreen plants were completely inactive in winter and therefore needed no attention until balmier weather arrived. Today we know better. Deciduous plants shed their leaves annually as they move into dormancy. But dormant simply means “not actively growing”; underground, the roots, surrounding soil, and water collaborate to provide life support. Most current sources on successful gardening in the Southwest will tell you that you need to water your trees and shrubs, plus other newly planted additions to your garden, during the winter.

When I moved to Santa Fe nearly twenty years ago, I found this advice completely counterintuitive and ignored it, much to my chagrin. I didn’t realize that most plants that die in winter do so from lack of moisture, not from cold temperatures. After losing new trees and numerous perennials, I yielded to the admonishment to water during winter dry spells. According to horticulturalist David Salman, owner ofWaterwise Gardening LLC, water helps a dormant plant to maintain elasticity in its protoplasm and to produce the sugars, amino acids, and soluble molecules that are its nourishment. This moisture keeps plants resilient during the depths of winter.

John Muir poetically stated that “though to the outer ear these trees are now silent, their songs never cease. Every hidden cell is throbbing with music and life….” It is difficult to imagine an energetic ecosystem of fungi, bacteria, organic matter, and so on beneath the cold, hard ground. Perhaps it slows. But without soil moisture, it is seriously at risk. And all our plants rely on that ecosystem to grow and thrive. Lack of water stresses trees and shrubs more than any other factor I can think of. They will resist pest infestations and diseases with much more vigor if well tended during the colder months, when nature doesn’t provide ample snow or rain.

How do you water in winter, when hoses freeze, fingers go numb, and temperaturesmay not cooperate with a schedule? Here are some tips:

* Plan to water shrubs and trees deeply every 30 days. Water one- and two-year-old plants every two or three weeks. Once established with good root systems, plants should do fine with monthly irrigation.

* Use hoses, perhaps with bubblers or low sprinklers. Don’t forget to drain your hoses afterward.

* When we’ve had snow or rain and the soil is moist, there is no need towater. But even in winter the Southwest sun is drying; mulch helps to conserve moisture. Water in the morning, once the air temperature is above freezing. Soil that seems frozen will warm during the day and still absorb water. According to Salman, dissolving ice particles below the surface have the added benefit of aerating the soil.

* My last tip is to use native plants. Natives are best adapted to our climate and soils; they can survive extended periods of drought, temperature extremes, and animal predation. They tend to develop deeper root systems to anchor them against wind and to delve deep into the soil for nutrients and moisture.

Laurie McGrath has been a Certified Master Gardener in Santa Fe County for 17 years and is a founding member of the Santa Fe Native Plant Project (SNaPP). SNaPP is an advancedMaster Gardener training with the goal of educating the public about the many benefits of using native plants in the home landscape.

LAURIE MCGRATH The deep roots of a native shrub