That lush landscape you envisioned when you planted shrubs and evergreens this spring and summer could fizzle if you don't protect them from winter's icy fingers and harsh winds.
Without protection, even well-established shrubs and evergreens can be damaged by the cold weather ahead, experts say. Protecting them with windscreens, fences, lattices, deep watering and sprays that retain moisture will minimize damage.
"Weather patterns in winter can vary from year to year, sometimes harsh and other times mild, so I look at protecting shrubs from the drying effects of winds and sun as sort of insurance against damage. You never know when you're going to need it, but it pays to always be protected," says horticulturist Vincent Drzewucki, a 26-year veteran of the nursery business.
Drzewucki says to start by surveying the plants on your property. "Most often, there are several microclimates on your property that make winter protection necessary."
Exposure to wind and sun can vary from one side of the house to the other, he says, as well as on different sides of a fence, structure or group planting. "In winter, prevailing wind is typically out of the northwest, its drying effect causing windburn." Broadleaf evergreens -- such as rhododendrons, azaleas, hollies and laurels -- are most susceptible to wind damage because their wide leaves catch the wind. Evergreens with needles, such as spruces and junipers, are better-adapted to survive harsh winters without protection. The exceptions are dictated by the type of microclimate they are in. "Shrubs on the south and east side of a structure or planting usually fare better with little or no protection," Drzewucki adds.
Plants need a good soaking in the fall, the pros say.
"All plants, but especially evergreens, will come through the winter best if their root systems are well-hydrated before the ground freezes," notes the National Gardening Association's Susan Littlefield, editor of the NGA's online regional reports. Regular watering -- of newly planted shrubs, in particular -- is a must, she says, especially if fall weather is dry. "Give plants a good soaking in late fall, just before the weather turns really cold," Littlefield says.
Drzewucki agrees. "A few warm days in the fall can dehydrate shrubs, so make sure they are well-hydrated going into winter," he says. "Continue watering if needed until the ground freezes." Shrubs need about an inch of water per week to remain sufficiently hydrated. "If rainfall is lacking, supplement it with irrigation from sprinklers or your hose."
There are many ways to protect plants from windburn and snow damage, says Randle Siddeley, an internationally known garden designer. In one project, he installed V-shaped support frames over large planting areas. Covered in a special fabric membrane that allows air and water to pass through, the frames prevent damage from snow and wind.
"Frames need to be thought out, like a stage set in your garden, and well-built," Siddeley says, so that they don't collapse under the weight of snow. Ironically, a heavy, dry snow, if it doesn't go through a rapid melt/refreeze cycle, can be a great plant insulator. An early snow that stays is best, he says. "It's when it melts and freezes that a lot of damage is done."
Many pros recommend using an anti-desiccant or anti-transpirant spray, such as Wilt Stop or Wilt-Pruf, "a clear protective spray that seals in moisture in the shrub leaves," according to Drzewucki. "A second application may need to be made in late winter because late February and March weather can be harsh and these sprays wear off over time."
Plants develop their natural hardiness best when the temperatures fall gradually, he adds. "A year with a warm late fall and then a sudden cold spell may leave plants more vulnerable to injury. There's not much you can do about this. Accepting the vagaries of nature is just part of gardening."