18 September 2023- Fall officially kicks off Saturday, September 23, 2023—the same day as the autumn equinox—in the Northern Hemisphere. Many of us in Maryland are looking forward to leaving behind the days of record-breaking heat and welcoming clear, blue skies, cooler evenings and autumnal tree canopies. The Maryland Department of Natural Resources once again will present its weekly Fall Foliage Report, posted online and sent by email bulletin to subscribers.
What can we expect from fall foliage this year and when can leaf peepers catch a glimpse of fall’s best colors?
What the Science Says
For years, scientists have worked to understand the changes that occur in trees and shrubs during autumn, according to the United States Department of Agriculture Forest Service, but they can agree that three primary factors influence autumn leaf color: leaf pigments, length of night, and weather.
Maryland Department of Natural Resources State Forest Manager Melissa Nash explains. “During the warmer summer months, leaves are green due to the chlorophyll pigment. Along with that green pigment are hidden yellow to orange tones called xanthophyll and carotenes (these are the same type of pigments that give carrots their orange color).”
But what causes the transition from green to shades of orange, yellow and red? Nash points to the length of daylight and cooling temperatures characteristic of fall months.
“As fall approaches, changes in the length of daylight and decreasing temperatures cause the leaves to stop their food making process of photosynthesis. When this happens, the chlorophyll breaks down and the green color begins to disappear, revealing yellows and oranges. Around this same time, some trees also produce pigments called anthocyanins which cause red to purplish tones.”
So when can we expect to see the leaves start to change in Maryland? The Department of Natural Resources’ foresters offer their expert predictions, beginning with the state’s westernmost counties.
Aaron Cook, State Forester, Indian Springs Wildlife Management Area
“The early leaf out and summer long dry weather will negatively impact fall foliage in western Maryland, particularly Frederick and Washington counties. Here in western Washington County the Fairview Mountain ridge is displaying some color, but unfortunately it is the result of leaf drop from drought stressed trees (see attached photos from Indian Springs Wildlife Management Area, showing “fall” color on the ridge, early leaf change of black walnut, flowering plum, and linden). In Frederick county, most of the black gum and sweet birch have already lost their leaves due to drought stress; they did change color, but leaf drop immediately followed. A well timed tropical storm could help offset drought conditions, but will likely not reverse the course on drought stress impacts to fall color from an entire growing season of drought conditions. Time will tell though, as the oak dominated ridges are normally hitting peak in the latter half of October.”
Melissa Nash, State Forest Manager, Mt. Nebo Wildlife Management Area
“If we don’t get some rain, I don’t think it’s going to be a spectacular year like we had last year. Hot and dry just doesn’t bode well for fall color. We are already starting to see a few subtle hints in Garrett County.”
More 2023 Fall Foliage Predictions
- Our friends at The Farmer’s Almanac predict that much of New England will be at or near peak fall color by October 11; a little further south in the Blue Ridge Mountains, it looks like mid-October is our best bet for peak fall color.
- According to the Washington Post, Maryland should see peak colors by mid-October with an ultimate peak arriving around Oct. 23. The northern half of Virginia should be past peak by then.
Calling all Leaf Peepers and Outdoor Enthusiasts!
Join us as we follow the fall transition each week with reports from our natural resources experts at our state forests and parks! Back by popular demand, we welcome all of Maryland’s outdoor enthusiasts to send in photos capturing the beauty of the fall season. Please use the submission form to submit your entries directly to us. Your photo might be selected to appear in a future edition of the Fall Foliage Report!