CHICAGO (CBS) – Chicago’s hot, dry weather already has some trees and shrubs showing fall colors at the Morton Arboretum.

WBBM Newsradio’s John Cody reports gardeners can’t water everything, so they have to prioritize: vegetables, prize trees, and shrubs.

Morton Arboretum horticulturist Sharon Yaizlee said young trees with shallow root systems are particularly vulnerable to high temperatures and low rainfall.

“We see a lot of damage with Japanese maples. They tend to scorch when the weather gets hot and dry, like it is now” she said. “We also see problems with a shrub called serviceberry.”

LISTEN: WBBM Newsradio’s John Cody Reports

Yaizlee said some serviceberry shrubs are already turning brown, or showing signs of fall colors — orange and red shades creeping onto the leaves — even though it’s still officially spring.

“It’s a sign of stress,” she said.

Yaizlee said the Morton Arboretum has recorded 9 inches less rain this year than last.

She recommended homeowners who want to water their trees use long period trickle irrigation away from the trunk, out under the leaves, to do the most for the trees – consistent with local watering regulations.