COLUMBIA — There's still a chance for lovely fall foliage in Missouri this year, despite an ongoing drought that could make the color change less vibrant than past seasons.
The determining factor will be the weather that occurs between now and mid-October, when color typically peaks.
- Sugar maples
- Sweet gums
- Scarlet oaks
- White ashes
- Black gums
- Shag-bark hickories
- Tulip poplars
To help ensure healthier foliage next year, Missouri Department of Conservation resource forester Angela Belden offers the following tips:
- Cut or thin out undesirable plants to allow more sunlight and water to reach the optimal trees.
- Plant species that are native to Missouri climate, so they're better prepared to combat drought and other harsh weather.
- Check the buds of trees thought to be dead. If the buds are moist, the tree is probably dormant and will most likely come back healthy next season. Don't remove the tree prematurely.
Stephen Pallardy, an MU forestry professor, said about 10 percent of the forests' foliage is gone because of the drought.
“It’s kind of hard to predict after this summer,” Pallardy said of the color change. “The drought was so severe that there’s probably going to be less than normal. We’ve lost a lot of foliage. Obviously, if it’s not there, it can’t turn color. … (This year) will probably be muted compared to other years.”
Pallardy said the ideal weather for fall color over the next few weeks would be sunny days with temperatures around 60 degrees and nights with low temperatures in the 40-degree range. Any frost would kill the leaves.
Cool temperatures trigger the loss of chlorophyll that keeps the leaves green. That, in turn, allows the fall colors to show through.
Some plants have gone dormant, and some have closed the stomata on their leaves to defend against the drought. By closing the stomata, leaves keep water in but carbon dioxide out, which causes sugar production to decline.
Sugars in the leaves are the building blocks of some pigments in autumn. This season's sugar production is down due to water stress from the drought.
According to the Missouri Department of Conservation website, the yellow and orange colors of some leaves are hidden within their carotenoids. Red and purple colors, however, are created on warm fall days, when sugar is produced and trapped in the leaves during cool nights. The colors occur when the sugars chemically change into anthocyanins.
A portion of Pallardy’s field work measures the hydration of leaves and is showing that leaves are coming back to pre-drought levels of hydration. Recent rains have helped revive some of the plants, but others have already gone dormant.
Dormancy is the appropriate response, Pallardy said. Plants that re-sprout when it rains risk being weaker next year because their leaves will not have time to fully mature before winter weather and freezing temperatures begin.
Yellow will be present because it already existed in the leaves before the drought started, Pallardy said. But it remains to be seen how the violets and crimsons will develop.
Angela Belden, a resource forester with the Missouri Department of Conservation, said the intensity of fall foliage involves many factors.
“It’s sort of like looking into a crystal ball when you’re trying to predict fall colors because there’s so many microclimates and other aspects that play into it,” Belden said. “If we continue to have this nice cool weather with sun, then we might have a chance at some pockets of really good color.”
She suggests that aspiring leaf peepers stick to lower topographies and stay near waterways to see more of an array of colors this season. The Katy Trail, the bluffs along Highway 94 east of Jefferson City and anywhere along the Missouri River are vantage points suggested by the experts.
The Conservation Department posts foliage updates on its website. The first 2012 post will be at 5 p.m. Thursday and will run until the fall color has ended for the season. The foliage will turn in northern Missouri first, and the color change will progress steadily south through October.
Supervising editor is Scott Swafford.
Are you seeing signs of fall? Take a picture and send it to submissions@ColumbiaMissourian.com, or post it on our Facebook page. And check out this album of last year’s gorgeous fall photos from readers.