The garden sleeps, yet it is very much alive. With the ground frozen down only a few inches so far, roots of perennials, shrubs and trees continue seeking nutrients and moisture to survive, though without their leafy green canopies, their needs are much less.
Still, without a protective blanket of snow or any other appreciable form of moisture, our plants rely on our attentiveness to get them safely through our long winters. The following three winter chores -- mulching, watering and tree-wrapping -- will give you something useful to do on the next warm day in your garden.
If your plants went into this dry winter well-watered, mulches will help to keep the soil moisture from evaporating into the dry air. Winter winds subject plants to desiccation, so be sure you've watered a wide area around the plant thoroughly, not just the plant itself. Otherwise, the surrounding dry soil will simply wick away your meager allotment, and you'll be watering again in a week.
Mulches of tree bark, pine needles or aspen humus, spread to at least the drip line of the plant, about four inches thick (two inches for the aspen humus) should keep your watering regimen to once every one or two months. Depending on your soil (sand needs more water, clay needs less), wind and sun exposure, and moderating hardscapes (stucco walls, asphalt driveways, etc.), it may be more or less. You are the best judge. A hand in the soil and some time-tested experience and intuition always helps.
Newly planted or young trees with developing root systems are most at risk. Though established trees can withstand a lot more drought, they too will not leap lustily into spring if deprived of moisture for too long in the winter. Knowing the unique water needs of your different plants helps too. An established apple tree, for instance, will need more consistent moisture than, say, a ponderosa pine tree which has evolved to survive periods of drought in nature.
Along the edge of an open area of our meadow we planted juniper and cedars five years ago, and some low-growing juniper this summer. Several large ponderosa pine dominate the area, their root systems drawing moisture from the sandy soil which is covered with native sages, penstemons and prairie grasses. Over the years, I've noticed the soil in this area dries out quickly due to exposure to winds and the southerly slope of the land. I hooked up the hose to the closest hydrant, attached a sprinkler and gave the young plants a good drink by soaking the entire area for three hours in the middle of the day. This watering should keep them safe in case we have another two dry months.
Dry winters are hard on birds also. I keep our tube feeder filled with black oil sunflower seed, the food preferred by most birds. I sprinkle cracked corn and whole corn cobs on the ground for the jays, and keep the suet feeder filled for the woodpeckers and nuthatches. The birdbaths are kept full, and filled with fresh water daily. We have noticed the birds prefer bathing in the cement bowl rather than the plastic bowl with the built-in heater, I think because their feet can grasp the rough cement bottom while they splash around. So if you're thinking about buying a heated birdbath for your birds to bathe in and drink from, buy a heater you can put in a concrete bowl.
Another winter challenge for our plants, especially young, thin-barked deciduous trees, is sunscald. Colorado winter day temperatures often reach 60 degrees, and the high intensity sunlight hits trees at a lower angle in winter, heating up the trunks on the south and southwest side during the day. The heat brings the cells along the trunk out of dormancy, and they begin moving fluids in the connective tissue. After sunset the temperatures usually drop below freezing, and the freezing kills these activated cells. This injury may later appear as discolored bark, and may fall off in patches of dead bark, showing dead tissue underneath.
The trees most susceptible to sunscald are honey locusts, fruit trees, ashes, maples, lindens and willows, in addition to all new trees brought to Colorado nurseries from milder winter climates like the Pacific Northwest or the Midwest. I wrapped all of our new trees (anything four years old or newer) with a commercial tree wrap made of crepe paper to insulate the bark and prevent sunscald. Beginning at the base of the trunk and moving upwards, I overlapped the paper about 50 percent, to the point just above the lowest branches, and secured the wrap with twine. I'll be sure to remove the tree wrap in April to allow natural seasonal growth and avoid possible insect damage. Wrapping new trees each winter is essential for several years until the bark thickens and is less prone to sunscald damage.
Winter is nature's rest period, so it's natural now to find ourselves wishing to take a well-deserved rest from the tyranny of the summer garden. No pots to water, lawns to mow, weeds to pull, veggies to harvest. Though we may think of winter as "down time" in the garden, I find there is still lots to do in caring for the health of my plants through the winter. And I know this caring will reward me a hundredfold with vigorous, vibrant plants next summer.
-- Laura Spear is the owner of ForestEdge, a private garden in the Black Forest. You may e-mail her at: firstname.lastname@example.org.