Some native New Yorkers “live fast and die young,” says Uli Lorimer of the Brooklyn Botanic Garden, standing in front of a sassafras tree. “As beautiful as it is, it only lives 60 to 70 years, sometimes only 20.”
More stable native New Yorkers, he says—“blue-bloods” like oak, hickory and beech—reside along leafy streets in rich soil for hundreds of years.
Native New Yorkers can also be parasites, such as the squaw root, which treats oak trees like sugar daddies, draining their syrup.
Then there are those native New Yorkers, the bladderworts, who lure naïve young prey (fleas, tadpoles) into their trap. “The whole process takes about 1/200th of a second,” Lorimer says with admiration.
Lorimer is the curator of the Native Flora Garden, which is celebrating its centennial this year with a series of talks, tours, exhibitions and new signs. The Local Flora Garden, as it was originally called, was the first completed garden within the , beginning the transformation of what had been an open field and a coal ash heap.
Making native flora a priority was a wise and prescient choice, Lorimer believes: “Our founders realized a hundred years ago that our local plants were under threat.”
Indeed, you can carry this metaphorical connection between people and plants just so far. Any New York mayor will tell you that the city has thrived because of its immigrants, but this is true only if you are talking about its human beings. Lorimer himself is an immigrant, arriving from Germany when he was 6 years old; but when it comes to plants, the gardener is a nativist. Native New Yorkers—those that have existed in this region for thousands of years—are better for the environment in just about every way, he says.
“If you love New York, you should love New York plants," Lorimer says.
On any given piece of land in the region these days, Lorimer guesses that some 30 to 40 percent of the plant life is non-native, and this alarms him. Some are innocuous, “naturalized” (they don’t push out other plant life). But too many are what horticultural experts like Lorimer call invasives.
The introduction of foreign flora and fauna offers one sad tale after another. Insects shipped into U.S. docks in packaging material carried a fungus responsible for Dutch Elm Disease. “Elms used to be one out of every four street trees in the nation. Now they’ve almost disappeared," he says.
There is particular poignancy and irony for residents of Brooklyn in the story of The Tree of Heaven. It is an invasive plant from China. It is also the titular tree of Betty Smith’s 1963 novel, “A Tree Grows in Brooklyn.” The problem with this tree, whose official name is Ailanthus altissima, is that, no longer being naturally curbed through predators and diseases as it is China, it is crowding out native New York trees, such as oak. Why is this a problem? “The Tree of Heaven supports five to six species of butterflies,” Lorimer explains. “The native oak supports 400 to 500 species of butterflies.”
In other words, “invasives don’t support the larger ecosystem," he says.
Thirty years ago, the scientists of the Brooklyn Botanic Garden began a survey of the local flora, and thus have tracked the disappearance of some once-common and beautiful plants, such as the Grasspink orchid.
“We’re losing our natural diversity. It’s a little depressing,” says Lorimer.
He seems to cheer up, though, as makes the rounds in the garden he oversees, which is open from April to November. Tall, with hat and dark glasses, wearing a green uniform loaded down with utility belt full of gardening tools, he looks like your friendly forest ranger as he points out highlights along the path—a Black Cherry tree full of moss, the only plant that was there before the Native Flora Garden was put together. He cuts the root of the sassafras, which was once used to make root beer, and demonstrates how it tastes more like lemon. Then he cuts a birch root and offers a taste—now that’s root beer. He slices an aptly-named blood root, and, like a scene out of a horror movie, it starts to bleed. “The sap is red,” he explains. “They can use it to dye textiles.”
He points lovingly to the swarm of bees around a Hills-of-Snow hydrangea: “The bees prefer the natives plants because that’s what they’ve been eating for thousands of years.” He holds up a leaf with a circle cut out of one end, a circle so perfect it seems cut by a hole puncher. “This is how you know that the leaf-cutting bee is here,” he said. The leaf-cutting bee—that’s its official name—is one of the 225 species of bees in the region. He suddenly looks grim. “20 of them are non-native.”
Tours of native flora are held at the Brooklyn Botanic Garden on Wednesdays starting at 1 p.m., Saturday and Sundays at 3 p.m. Meet in front of the Visitors Center.