The drought hasn’t been too kind to fans of leaf-peeping, causing some trees to start shutting down early, but recent temperatures have helped.
“Even with all the drought, you still see color because it is already in the leaves from the rainy weather we had this spring,” said Steve Roberge, professor of natural resources and UNH Extension forestry specialist. “What has been great so far are these lovely 45 degree nights that help to bring out the first reds and deep purple colors.”
When the days are warm, around 70 or 80 degrees, and the temperature drops back to around 40 degrees at night, the trees’ cells start to break down sugars. That causes the production of green chlorophyll to slow down. Then hidden pigments in leaves — yellow and brown or red and orange — then get revealed.
Each tree species starts to shut down chlorophyll production at its own pace, with red maples in low-lying areas and swamps showing off their colors as early as mid-August. Other species like oak, ash, birch and other maples need the long cool nights.
“People always ask me when peak leaf peeping season is going to be, and I always say whenever you have the time to get out and enjoy it,” said Roberge.