“When you start thinking about the timing of seasons, and when it goes awry, there are consequences not just for plants, but for pollinators and, eventually, for people.”
The U.S. Department of Agriculture in mid-November updated its plant hardiness map, a resource that helps gardeners nationwide determine which plants would thrive in a given region. Last updated more than a decade ago, the new map shows a warmer Lehigh Valley. While experts said the change in zones has little immediate impact, the map illustrates a warming climate, stressing the need to mitigate any further effects while building resilience to those already here.
The majority of the Valley — including Allentown, Bethlehem and Easton — have moved from zone 6b to 7a, according to the latest map. Based on 30-year averages for the lowest annual winter temperatures, the region warmed from -5 to 0 degrees to 0 to 5 degrees.
For many gardeners and farmers, the updated map only confirmed what they have already suspected for years.
“For a lot of gardeners, they said ‘This confirmed exactly what I was thinking – something is happening.’ Now, we have the map that says, ‘Yes, we've gotten warmer.’
Natasha Woods, an assistant professor of biology at Moravian University
“They just didn't have the verbiage,” said Woods. “For a lot of gardeners, they said ‘This confirmed exactly what I was thinking – something is happening.’ Now, we have the map that says, ‘Yes, we've gotten warmer.’
“And that makes a difference for some plants — that makes a difference.”
‘It's climbing up’
The plant hardiness zone map, developed by Oregon State University’s PRISM Climate Group and the USDA’s Agricultural Research Service, is divided into just more than a dozen zones, with each representing a 10-degrees-Fahrenheit range of temperatures. Each zone is further divided into two half zones, with each representing a 5-degree range.
The new plant hardiness map incorporates data from 13,412 weather stations, compared to the 7,983 that were used for the 2012 edition, officials said in a news release announcing the updated map.
Courtesy
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U.S. Department of Agriculture
The U.S. Department of Agriculture in mid-November updated its plant hardiness map, a resource that helps gardeners countrywide determine which plants would thrive in a given region.
And the Valley isn’t the only region that warmed — half the country did, too.
“Overall, the 2023 map is about 2.5 degrees warmer than the 2012 map across the conterminous United States,” said Christopher Daly, director of the PRISM Climate Group and the map’s lead author. “This translated into about half of the country shifting to a warmer 5-degree half zone, and half remaining in the same half zone.
“The central Plains and Midwest generally warmed the most, with the southwestern U.S. warming very little.”
“My records show that it's climbing up,” Buse said. “The graphs I have show that it’s increasing.”
Courtesy
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Fred Buse
Fred Buse, a master gardener who has tracked climate change for 40 years from his Allentown home, has been taking note of the high and low temperatures each day. Compiling the data, he can show how the average temperature has warmed over the past several decades.
Looking at the plants that thrive in different zones, there isn’t too much difference between 6b and 7a, Buse said, but residents can see the change in timing.
“The perennials are going to bloom earlier, and the trees are going to develop the leaves earlier,” Buse said. “It's also important for the farmer's crops, too, because the crops which might have needed cold weather, they have to move that further north.”
1 of 23 — Fred Buse, phenologist
Fred Buse sits at his kitchen table and observes wildlife in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
2 of 23 — Fred Buse, phenologist
Fred Buse sits at his kitchen table and observes wildlife in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
3 of 23 — Fred Buse, phenologist
Fred Buse sits at his kitchen table with his book Anticipation. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
4 of 23 — Fred Buse, phenologist
Fred Buse observes wildlife in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
5 of 23 — Fred Buse, phenologist
Fred Buse makes notes of the day's weather and wildlife that has visited his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
6 of 23 — Fred Buse, phenologist
Two charts on Fred Buse's computer show monthly mean temperature in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
7 of 23 — Fred Buse, phenologist
A chart on Fred Buse's computer shows the declining February House Sparrow population over 32 years. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
8 of 23 — Fred Buse, phenologist
Fred Buse walks in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
9 of 23 — Fred Buse, phenologist
Fred Buse observes wildlife in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023.
Donna S. Fisher
10 of 23 — Fred Buse, phenologist
A male Hairy Woodpecker visits Fred Buse's yard . Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
11 of 23 — Fred Buse, phenologist
Fred Buse feeds the goldfish in his backyard pond. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
12 of 23 — Fred Buse, phenologist
Fred Buse leans on a pin oak tree he planted in the early 1980s. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
13 of 23 — Fred Buse, phenologist
Fred Buse shows pictures of his South Whitehall backyard as he was landscaping it many years ago. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
14 of 23 — Fred Buse, phenologist
Fred Buse observes wildlife in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
15 of 23 — Fred Buse, phenologist
Fred Buse observes wildlife in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
16 of 23 — Fred Buse, phenologist
Fred Buse sits at his kitchen table and makes notes on his observations of his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
17 of 23 — Fred Buse, phenologist
A blue jay visits Fred Buse's backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
18 of 23 — Fred Buse, phenologist
This is the view looking out the kitchen window of Fred Buse. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
19 of 23 — Fred Buse, phenologist
Fred Buse checks his bird feeders in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
20 of 23 — Fred Buse, phenologist
Fred Buse looks over the asparagus growing in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
21 of 23 — Fred Buse, phenologist
Fred Buse looks at the holly in his backyard. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
22 of 23 — Fred Buse, phenologist
Fred Buse checks on his vegetable garden at the front of his home. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
23 of 23 — Fred Buse, phenologist
Fred Buse, a former marine engineer, peers through an impeller that was part of a working pump and is now a wind chime on his patio. Fred Buse, 87, of South Whitehall Township, has been tracking climate change in his Allentown backyard for decades. Every day he records the high and low temperatures, precipitation, insects, birds and other animals. He has written “Anticipation: The Effects of Climate and Environmental Changes on the Annual Cycle of Life on the Flora and Fauna in a Suburban Backyard,” which was published in 2021. Picture made Wednesday, November 8, 2023
Donna S. Fisher
‘The plants have noticed’
Eli Stogsdill, a project manager and farmer at the Monocacy Farm Project, said they’re trying to build resilience and, at the same time, diversify their crops to keep up with the warming climate.
“In addition to the types of vegetables that we're planting, we're also planting some of the trees and tree crops as ways to have annual and perennial plants and ecosystems that we're working with so that there's just more partners to be navigating the changing climate with,” he said. “And, in a year where certain crops might have a hard time, we're not entirely dependent on them for our work.”
“Part of our work is to demonstrate and show people these things and to be a place where people can observe some of these changes and to talk about them, engage with them,” Stogsdill said. “That's the kind of thing that farms like ours and other projects throughout the Valley should be open to exploring and the type of educational program that we could be building that actually builds useful data for people that are trying to plant and grow and navigate these changes.”
As climate change continues, plants either adjust to new conditions, or they don’t, Woods said.
“If we had been looking at this more frequently, we would have already noticed these slight changes that are getting warmer and warmer,” she said. “But the plants have noticed, and the plants are making adjustments as a species.”
For example, the sugar maple, a flowering plant, has adapted to a colder environment. As the region warms, those plants will seek cooler temperatures.
“But, at the same time, species that normally are not here will start to migrate from the south to this northern climate because it's getting too hot for them down south,” she said.
While short-term or seasonal gardening may be less impacted, it’s plants that can live for hundreds of years, like trees, that now need more consideration.
“If you want longevity, you're going to have to start thinking about how the climate is changing, and plants that thrive in these warmer areas in the U.S. and we are projected to have warmer temperatures here,” she said. “Then, find out which species are doing well in those zones and you can start planting those here and seeing, over time, how well they adjust.”
I cover environment and science for LehighValleyNews.com. Originally from Schuylkill County, I got my start in journalism writing obituaries for the Reading Eagle in 2014 after graduating from Kutztown University. I’ve also reported for The Press of Atlantic City, covering municipalities, crime and courts, and The Morning Call, where I was part of the audience team. In 2022, I won first place in the diversity category of the Pennsylvania NewsMedia Association’s Keystone Media Awards. Contact me at mollyb@lehighvalleynews.com or 610-984-8225.
