By Liz Nye, New England Botanic Garden Staff
September 2023

Apple season is in full swing, but visitors won’t find any growing at the Garden—at least not yet. This fall marks four years since the Garden cut down its historic apple orchard, razing the mature trees in order to save its rare collection of heirloom apples from a devasting plant disease called fire blight. The young apple trees that today’s visitors see standing in the old orchard’s place are still in their infancy, growing slowly but surely. Last May, some even had their first blossoms.  The apple orchard at New England Botanic Garden

Eventually, the Garden’s Frank L. Harrington Sr. Orchard will again give people the opportunity to taste uncommon apples like the ‘Westfield Seek No Further,’ ‘Yellow Bellflower,’ and over one hundred others, some that were first cultivated as far back as the seventeenth century. In the meantime, work to ensure the success of the 250 replanted trees continues. Some of that work is now taking shape through academic partnerships.  

Over the summer, the orchard was visited by researchers from Washington State University’s Apple Genome Project. The project aims to create a genetic fingerprint of every apple on the planet. The Garden’s collection, begun during the Great Depression by Worcester County Horticultural Society member Stearns Lothrop Davenport, contains 30 to 40 varieties that are exceptionally rare and so far, genetically unmapped.  

“Heirloom crops chronicle a region’s history,” says Mark Richardson, director of horticulture at the Garden. “If heirloom varieties are lost — as might have happened with our orchard — with them could go any undiscovered genetic traits, like novel resistance to drought, pests, and diseases, that might benefit tree breeding research programs in the future,” he says. This is especially important in the age of climate change. 

Fire blight, the disease that precipitated the 2019 orchard restoration, is accelerated by climate change. Caused by the bacteria Erwinia amylovora, fire blight, as those who have followed the orchard’s restoration journey will know, affects plants in the rose family like apples and cherries. It spreads in rainy, warm weather when air temperatures are above 75 degrees Fahrenheit. Carried on the bodies of honeybees, the bacteria can move quickly from tree to tree when apple blossoms are open.  

“Plants have many different defenses to diseases, but diseases figure out mechanisms to get past those defenses and into plant tissue. Entering a plant’s vascular system through the flower is pretty ingenious,” Mark says. The effect is quickly observable. Fire blight infected trees look burned or charred. Eventually they die. While fire blight sounds dramatic, and it is, it was once only a minor concern because while apple blossoms are open in May, conditions were rarely warm and wet enough in New England to facilitate the spread of the bacteria.  

Human-caused climate change means warmer springs, a trend expected to c