Snow falling on cedars – and other kinds of trees and shrubs in the Northeast and mid-Atlantic states this winter – has caused serious damage that can be remedied, according to experts at Cornell Plantations.

The Plantations horticulturists, who tend more than 700 acres of botanical gardens, natural areas and the F.R. Newman Arboretum at Cornell University, are still assessing storm damage from the unusually snowy winter of 2002-03. They offer to private property owners some advice, which they plan to follow themselves, for the restoration of greenery.

• "Remember that not all the winter damage is yet visible," says Plantations' Director of Horticulture Mary Hirshfeld. "Once the accumulated layers of snow begin to melt away, most likely more fallen branches and shrubs that have been broken by falling limb will be revealed." Plantations workers are calling accumulated damage to the university's famed rhododendron collection "the lasagna effect," but Hirshfeld says it's more like a multilayered ice-cream sandwich. "Be patient. Wait for the snow and ice to melt, then see what you have to work with," she advises.
• Jagged stubs from fallen branches should be cut back cleanly to the branch collar, with pruning clippers or a pole saw, so that wounds can heal quickly. But damage to larger specimens might merit the attention of professional arborists. Hirshfeld calls major tree work a dangerous, strenuous business and warns, "Keep those pole saws away from electric lines."
• Shrubs that have been crushed often can be cut back to 4 to 5 inches above ground level, permitting them to resprout. "Suckering shrubs, such as shrubby dogwoods, respond well to this treatment," Hirshfeld says. "Clump-forming shrubs, such as fragrant viburnum, will be slower to regain normal size and form, and always will bear the marks of this corrective pruning." Techniques are taught in publications such as "An Illustrated Guide to Pruning Ornamental Trees and Shrubs" from Cornell Cooperative Extension http://www.cce.cornell.edu/publications/catalog.html .
• Small trees and large shrubs that spent the winter with their tops bent over beneath the snow might spring back to a vertical position once the snow has melted. "Give them some time," Hirshfeld suggests, "and if they remain bent, cut them back either to 4 to 5 inches above ground or to a point below where they have been bent. Use judgment and think carefully about how the plant will respond, where it will break new buds and what form the pruning cuts will encourage."
• Spring thaw is a good time to check for hidden rodent damage to stems and surface roots. "Tunneling rodents, particularly voles, may have moved beneath this winter's long-standing snow cover," Hirshfeld says. "Make plans to protect plants from rodents -- or whatever else is eating them -- before next winter."

If plants are so badly damaged that they must be removed and replaced, try to learn from experience and plan accordingly, says Hirshfeld. This spring, for example, Cornell Plantations arborists will replace spruce budworm-infested evergreens with disease-resistant varieties. County Cooperative Extension agents can advise property owners about appropriate varieties for differing local conditions, Hirshfeld says. She recommends publications with localized information, such as the pamphlet series from Cornell Plantations and the Urban Horticulture Institute, "Tough Trees for Tough Sites." These are keyed to plantings that can be viewed at the university.

"Before you invest in a new tree or shrub, try to visit a local public garden or arboretum, see what's thriving in your area, ask lots of questions and learn from others' experience," Hirshfeld says.

As for the 2002-03 storm damage after a string of milder winters, Hirshfeld tries to look to the bright side. "Hopefully, nature will give us a break now, and we can get on with the healing."