Casualties include hydrangeas, camellias, butterfly bushes, fig trees, Southern magnolias, crape myrtles, laurels (both skip and cherry), mahonias, nandinas, rhododendrons, ferns and other perennials, arborvitae, red cedars, hollies, skimmia, rosemary, sage, lavender, and thyme.
Many an evergreen is windburned and brown. Quite a few roses, including some vaunted Knock Outs, are KO'd. Even English ivy, usually bulletproof, is struggling.
"And we all thought we wouldn't have a cold winter again," says Becki Szkotak of the Rutgers Camden County Cooperative Extension, which is fielding calls from homeowners unused to such extensive winter damage to their plants.
Experts caution against jumping the gun and ripping out damaged plants until you're certain they're a lost cause.
"Patience is what we need. Wait before replacing," says Fran Lawn, landscape management director at the Pennsylvania Horticultural Society.
Lawn lost wood fern and ginger perennials in his home garden over the winter but has seen other plants perk up, albeit three weeks later than they did after recent, milder winters.
"We've become accustomed now to an early spring, so really, I feel like we're having a normally scheduled spring this year," says Lawn, who recommends waiting two more weeks before deciding whether a plant stays or goes.
A scratch test might be useful.
Lightly scratch your fingernail along the bark or stem. If it's green underneath, your plant's alive. If it's brown and brittle, do a little pruning to determine if there's any life closer to the base. If not, you have your answer.
Regardless, steel yourself for hydrangea heartbreak.
Many mophead ( macrophylla) and lacecap varieties, whose 2014 buds were set in 2013, died down to the ground this year. This means that even if leaves sprout at the base of the plant this spring, there will be no blooms till next year. (You should cut back all the dead sticks now.)
Hydrangeas that bloom on new spring wood - panicle types, which have white, cone-shaped flowers, and arborescens like 'Annabelle' - should do OK. So should the oakleaf, a U.S. native.
Fig trees, which also died back this winter, are another cause for consternation. Cold-tolerant figs, such as Celeste or Chicago Hardy, might produce fruit this year. Many nonhardy types, small or young figs, or those in exposed locations likely were wiped out.
In early spring, Phil Forsyth, executive director of the Philadelphia Orchard Project, which has planted 34 orchards and supports 45 more around the city, grew increasingly alarmed at the state of the fig trees he was seeing. They all looked dead.
About three weeks ago, several began to sprout at the base. Just last week, one of his own came back to life.
"Basically, all the wood above ground is dead and has to be removed, but shoots are coming up from the roots. I'm so relieved," says Forsyth, a landscape designer. "It made me believe a lot of other ones will make it, too."
(If you see new growth at the bottom of the tree, you'll get fruit - but not till 2015.)
This reinforces the idea that all figs should be caged or fenced for winter, wrapped in tarps, and insulated with fall leaves. "I've been telling people not to wrap and then we had this awful winter. It made me very depressed," Forsyth says.
Not all the news is bleak.
The colder winter and longer snow cover made for a spectacular show of spring bulbs. "The tulips were gorgeous this year," says Valdes-Dapena, the otherwise beleaguered Delaware County gardener.
And tossing dead plants doesn't have to be traumatic.
"If they don't make it through the winter, the heck with them," says Philadelphia Rose Society president Don Atkiss, who grows 100 roses in his Hatfield garden. "It gives us a chance to try a new variety."
And though loath to admit it, garden centers are seeing a much-needed boost.
Rich Flagg, owner of Flagg's Garden Center in Moorestown, hates to see people lose so much of their landscape, but "business is good," he says. "That's the upside for us."