“It’s a sad situation,” said my friend, the plant lover. “This climate change has gotten so bad that the plants are confused.”
Since I am often confused myself, this resonated with me.
“It’s the poor cherry trees,” said my friend mournfully. “They are blooming in November. Now they will never bloom next spring.”
My friend echoed a concern I have heard from other local gardeners. This fall has been much warmer than normal and some local ornamental cherries are indeed sporting pink and white blossoms. They are a welcome sight against the late fall grayness, but the flowers do seem a bit unnatural.
No matter what you think about causation, climate-related politics, remedies and long term projections, climate change is real. The cherry trees, however, have long had the ability to adapt to warm fall weather. Under the right conditions, fall blooms are absolutely normal for some species and varieties.
The spring/fall bloomers are generally varieties of the popular higan cherry or Prunus subhirtella, sometimes labeled Prunus x subhirtella for its probable origin as a natural hybrid of two other Japanese species. Michael Dirr, woody plant wizard and Professor Emeritus at the University of Georgia, says that true species higan cherries are rare. The weeping form, Prunus subhirtella var. pendula, is very popular, but the specimens that many of us buy in big box stores are actually weeping varieties grafted onto the five or six foot trunk of a sturdy upright cherry tree. If my neighborhood is any indication, these grafted weepers are widespread. Brian Funk, curator of the Japanese Hill-and-Pond Garden and the Japanese tree peony collection at Brooklyn Botanic Garden refers to at least some of the grafted specimens as “Franken-trees”, because he thinks they look like “mops or umbrellas or octopus trees.” He also believes the big-box specimens tend to be unhealthy as well as ungraceful and recommends buying non-grafted upright varieties instead.
It is also possible to buy non-grafted weeping varieties, which may be a better choice. They will also, most likely, be more expensive than those big-box specials.
One of the upright types, ‘Autumnalis’, features semi-double pink flowers. As the name indicates, it is more likely than other ornamental cherry trees to sport fall flowers, though in smaller numbers than it produces in the spring. It is also much easier to find than the species form.
‘Autumnalis’ and ‘Autumnalis Rosea’ can grow between twenty and forty feet tall and up to 30 feet wide. Generally the flowers are deep pink in bud, opening to lighter pink and aging to nearly white. ‘Rosea’ bears blooms that are somewhat darker than those of its ‘Autumnalis’ sibling. Like most ornamental cherries, the trees are fast growers, but are relatively short-lived, thriving for thirty to forty years. That said, Mr. Funk mentions a couple of non-grafted weeping cherries—Prunus subhirtella ‘Pendula’—that have survived in the Brooklyn Botanical Garden’s Cherry Walk since its original planting in 1921.
I love ornamental cherries for their blossoms, neat green leaves and smooth gray bark. I see them occasionally as street trees and they are the right size for modern street-side planting strips that are narrower than those of earlier times. More often they are used as small specimen trees in yards and gardens. If you have the room, plant a row on either side of a long driveway. The spring show is glorious.
Beautiful as the cherry blossoms are, they lack fragrance. The compensation, perhaps, is that the higan species trees produce small black fruits, which are infinitely more attractive to birds than humans. This makes the higan cherry a good addition to a wildlife garden.
Returning to the idea of “unnatural” fall-blooming cherries, I can’t help but think that the late-season blooms—when they appear—are a boon to any pollinators still buzzing around on warm, late fall days. Most plants have packed it in, so nutrition for the pollinators is much harder to come by.
Don’t listen to purveyors of garden wisdom who tell you that fall-blooming cherries will not flower the following spring. The trees are genetically hard-wired to produce a large flush of blossoms in spring and—if conditions are right—a smaller flush in fall. One season of blooms is not dependent on or affected by the other, which is a comforting thought for those of us who love cherry blossoms.
So, in your prioritized list of climate-related worries, put air pollution and melting polar ice caps near the top. Take fall-blooming cherries off the list. They are simply doing what Nature intended.