Sunday, March 30, 2014

Gardeners Help Trees, Flowers and Shrubs Recover from Winter

Nurseries expect high demand, as gardeners replace plantings damaged by the freeze and all that salt
Daffodil bulbs at Longfield Gardens, a Lakewood, N.J.,
supplier, benefited from many weeks of
sub-35 degree temperatures.

WSJ, March 25, 2014
The good news is that winter is officially over. The bad news is waiting for you in the garden.
The seemingly endless winter has created more than the usual amount of cleanup and damage-repair projects in backyards this spring. Below-average temperatures and significant snowfall east of the Rockies, and warm winter temperatures west of the Rockies, have each led to their own types of problems in your yard. In some cases, there are benefits. But mostly, the effects are negative.
Weeks of heavy, wet snow weighing on tree and shrub limbs may have opened them up to breakage, disease and structural problems. And unseasonably cold temperatures have left foliage burned and brown on many usually evergreen plants, such as the creeping fig plants that cling to brick walls in Charleston, S.C.
The plant should be actively growing around this time of year, says Amy Dabbs, horticulture agent with Clemson University's Cooperative Extension Service, who fields gardeners' questions from Charleston County. She tells people who see signs of new growth on a brown plant to carefully trim the burned leaves with hand pruners. If there is no sign of new growth by the end of April, she says, it may be time to replace.
Nurseries are expecting higher consumer demand for replacement trees, shrubs and perennials this year. Many, though, are expecting to feel a squeeze because spring's late arrival means there are fewer weekends of nice-weather selling before Father's Day, typically the end of the retail season. And many nurseries are facing a tighter supply of plants, a result of their own suppliers' snow- and ice-related losses.
"There are going to be plants that are just cooked. I hate to say it," says Rob Turnbull, president of Turnbull Nursery, in North Collins, N.Y. He is uncertain about how his half-dozen acres of raspberries, which propagate by sending up new shoots from stems and roots underground, fared with the ground frozen so long and deep.
Late-winter and early-spring freezes also can kill tender buds of camellias, magnolias and other early-spring bloomers, diminishing floral displays later on. Mold diseases may take hold on lawns as a result of long periods of snow cover amid cold, damp temperatures of 30 to 40 degrees Fahrenheit.
And during months of snow cover, deer have been reaching higher and ranging wider for plant material to munch. Gardeners are finding their shrubs bare of leaves up to four feet off the ground.  
Daffodil bulbs at Longfield Gardens.
"This winter will have devastated our flower beds and front entry shrubs," says Stephen Zehala, 75, a retired engineering manager in Galena, Ohio. "The deer ate the yews, rhododendron and holly bushes," whose tough evergreen foliage they avoided in the past, he says. "Prickly holly isn't fun for a deer to eat, I'm sure. They were pretty hungry." He expects to spend as much as $7,000 to have a nursery remove and replace the plantings.
Some garden elements, though, benefited from the winter. Spring-blooming bulbs such as tulips, daffodils and hyacinths need at least six weeks of near-freezing temperatures or else they look flimsy, says Hans Langeveld, co-owner of Longfield Gardens, a Lakewood, N.J., bulb distributor. The ideal, he says, is between 10 and 12 weeks of temperatures below 35 degrees Fahrenheit. Parts of New Jersey were below 35 degrees for 7 1/2 weeks, according to the National Oceanic and Atmospheric Administration.
And certain insect populations may have been driven back by the extreme cold, entomologists say, including the harlequin bug, which feeds on cabbages, cauliflower and broccoli in the South. Even so, Don Weber, entomologist with the U.S. Agriculture Department's Agricultural Research Service, cautions against getting too comfortable. The surviving insects will start laying eggs by May, he says.
Salt damage will be significant in many gardens this year. With so much spread on icy roads, steps and walkways this winter, many nearby plants have damaged foliage. Salt may also have affected the surrounding soil chemistry. Sodium ions replace other nutrients in soil and prevent uptake by plants.
Eric Barrett, an educator with the Ohio State University Extension in Youngstown, Ohio, suggests holding off on pruning salt-damaged shrubs and snow-damaged tree limbs until mid-spring. "You may think it looks dead, but it just needs more time for new foliage to emerge," he says. He suggests local gardeners replace roadside plantings that are truly dead with species that are more salt-tolerant, such as hollies and junipers. And next year, he says, "Put down sand instead of salt."
Winter in many places west of the Rockies was drier than average, meaning gardens there may be later to bloom and plants may be shorter in stature. In San Francisco's 4 1/2--acre Gardens of Alcatraz, Shelagh Fritz, garden manager, says the agapanthus, chasmanthe and calla lilies are two-thirds their usual height and blooming about a month late. "They all look dwarfed this year," she says.
This year's extended cold follows a warm winter in 2013 which was the 20th-warmest on record, according to the NOAA, and the winter before was third-warmest. As a result, many gardeners are selecting plants that once were thought to be only marginally hardy for their growing zones. The windmill palm is somewhat cold-hardy, growing reliably as far north as coastal North Carolina, says Tony Avent, owner of Plant Delights Nursery, in Raleigh, N.C. "In the mid-90s I couldn't keep them alive. Now you've got people growing them in New Jersey," he says.
During a recent mild winter, Bill McLaughlin, curator of plants at the U.S. Botanic Garden in Washington, D.C., decided to plant a hedge of 75 gardenias. "We have been looking quite Southern in our gardens," he says. "We wanted to go for it."
It will be a few weeks before he knows whether the gardenias are really dead or not, Mr. McLaughlin says. Either way, they won't look their best for visitors this spring. "The drying injury is significant," he says, evidenced by so many brown leaves. He plans on pruning them by about one-third which should clean up their appearance.

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