Drought may affect fall foliage

August 13, 1999|By BRUCE HAMILTON

Autumn's rich colors may give way to bare trees if the drought persists, according to horticulture experts.

They say it's too early to predict whether dry weather will dull fall foliage, but a lack of rain leads to leaves dropping early. Trees shed their leaves to survive in drought and some already have started.

"Plants may decide this year it is not beneficial for us to stay open for business, so to speak," said Mike Galvin, urban operations manager for the Department of Natural Resources Forest Service.

About 1.16 inches of rain fell in Washington County in July, according to weather observer Greg Keefer. The area's precipitation is more than 12 inches below normal.


Galvin predicts weaker colors will come out early and leaves will fall sooner. Water is essential for trees to synthesize proteins that create color, he said. As drought persists, leaves "scorch," or begin browning.

They progressively wilt and eventually drop. Trees will shed down each branch toward their centers, Galvin said. Once the "permanent wilting point" is reached, plants will not recover, he said.

"I wouldn't be surprised if we didn't have fairly normal fall color. I wouldn't be a doomsayer on that," said Bill Gimbel Jr., who heads the Maryland Department of Agriculture's plant protection division.

Tulip poplars will be yellow, maples will be red and oaks will be reddish-brown, Gimbel said. But some trees will lose a lot of leaves, he said. Fall colors depend on changes in day length and temperature, which cause leaves to shut down.

"At this point, to predict is a shot in the dark," he said.

Sandy Scott, horticulture consultant for the Washington County Cooperative Extension Service, said leaves are beginning to fall.

"It's the tree's mechanism for saving itself in a drought. It's just something built into the plant to reduce transpiration," she said.

Dry weather increases sugar content in leaves, according to Scott. "If there are any leaves left, they'll probably be a prettier color," she said.

Trees are "just sort of hanging in there. They are stressed, no doubt about it," she said.

At Fort Frederick State Park, trees are holding on to their leaves.

"We've seen a little bit of browning. We haven't seen anything as far as leaf drops. I don't expect a whole lot of colors at all," said Park Ranger Scott Forrest.

Dan Spedden, park manager at Greenbrier State Park, said he hasn't seen leaves dropping. "The majority of the trees seem to be weathering well," he said. Seven of the 75 white pines planted beside Echo Lake in the spring of 1997 died, but that's not unusual, Spedden said.

"We feel pretty lucky. Our biggest problem is with the lake's water supply," he said.

Visitation and revenue have dropped as a result, he said. In July 1998, the park took in $113,177, compared to $9,199 last month.

"You can blame that entire amount on the drought," Spedden said.

The Herald-Mail Articles