Oak Lawn Trees Dying of Thirst
Forester Heather Green says village trees showing significant symptoms of stress and injury from drought; residents who can afford to are encouraged to water parkway trees.
In her nearly 20 years as a forester, Heather Green has never seen a drought quite like the summer of 2012.
“I’ve never felt this apprehensive or concerned in my entire career,” Green said, forester for the Village of Oak Lawn. “This drought is more intense than anything I’ve experienced since 1994 when I graduated from college.
With much of the United States experiencing its worst drought since 1956, Green said that the village’s trees are showing significant symptoms of drought injury and stress.
“I’ve seen a lot of tip dieback,” she said. “That’s a pretty significant symptom that a tree usually won’t recover from and is a sign of decline. Usually a tree has been declining for awhile and you haven’t noticed.”
Trees grow from their tips, not at their base. Green can look at a tree’s branch and tell how it has been feeling the last couple of years. If the tips are getting smaller, the tree has been struggling.
“I wish I could water a lot more, but it requires labor, manpower, vehicles and water,” she said.
Many trees are beginning to show symptoms of abiotic leaf scorch where browning of leaves are scattered through the tree's canopy due to roots not getting enough water. While leaves are still green, a browning or yellowing occurs between the veins of the leaf.
Compounding the drought's effects, 1,200 ash trees infected with the emerald ash borer are slated this year for removal from village parkways. Oak Lawn's trees have taken a beating.
“If an insect comes along at this point you could get other things going on,” Green said.
Last week, she fielded a call from a frantic resident on the 9700 block of South Kolmar Avenue that her tree had dropped 20 percent of its green leaves in an hour, a symptom of leaf scorch.
Green said the extent of damage from the drought to trees wouldn’t be known for the next year or two. Even if the region does start getting rain, the damage has been done.
“I’m concerned,” she said. “I’m used to mortality. You’re going to lose trees to storm and disease and old age. It just seems excessive right now.”
CORRECT WAY TO WATER TREES DURING DROUGHT:
The Village of Oak Lawn’s forestry department, a division of public works, has prepared directions for taking care of trees during the drought.
- Tree roots spread 2 or 3 times wider than the height of the tree, so you need to water a wide area.
- To ensure that the water penetrates deep into the soil, water the tree slowly. An open low-pressure hose or a sprinkler on a slow mist, are the most effective methods.
- Move the hose or sprinkler in a circle under the tree’s “drip line” or canopy every 30 minutes until water has been applied to the entire root system. Young trees require two inches of water per week; older trees one inch of water.
- Conserve water by applying mulch to bare soil 2-3 feet from the base of the trunk (but not touching the trunk itself) to help retain moisture for the tree.
Local watering restrictions are in effect; odd-numbered addresses on odd-numbered days, and even-numbered addresses on even-numbered days are limited to watering between 7 to 11 p.m. only.
The village also encourages residents to water the parkway trees. Green admits that some residents don’t want to pay the added cost of watering trees in the public way.
“The trees really need water right now,” she said. “It would be beneficial to residents to water their parkway trees and keep them healthy.”