Combat Tree Stress in Drought Conditions

from the Morton Arboretum

The harshest Midwest drought in a quarter century is causing the “worst drought symptoms I have observed in my professional career," according to Kris Bachtell, Vice President of Collections and Facilities for . He urges area residents to be good neighbors and step out to help water trees and plants throughout the neighborhood that are showing stress.

“Plants and trees are so stressed that they not might make it through the drought without some help,” says Bachtell. That’s why Chicago-area residents are reporting leaves browning and dropping off trees months ahead, because leaves are where the trees loss most of their water, Bachtell says.

The symptoms of the drought include: wilted leaves, leaves with a gray-ish cast, scorched leaves, yellowing leaves (particularly interior ones) and dropping leaves. To stave off continued damage, Bachtell recommends area residents take these steps to help avoid damage from this record-breaking drought:

• Go on neighborhood patrol: Step out of your own footprint and water the trees on your parkway.
• Check on your neighbor’s yard: Pull the hose out of your yard to make sure that your neighbor’s plants that are stressed get water.
• Head down the street with water: Take a five gallon bucket of water down the street and water something that needs to be watered.
• Water weekly: Gardeners should continue to water plants weekly. Large, established trees should be watered every 2-3 weeks in dry periods.
• Check new plants frequently: Newly-planted trees, shrubs and perennials are still establishing their root systems and should be checked more frequently. Water into the root ball area and surrounding area deeply. This will encourage new roots to grow deeper into the soil. Plants should receive up to one-inch of water weekly.

• Check on these species: Drought-sensitive trees and plants likely showing the effects of reduced moisture include magnolias, Japanese maples, dogwoods, beeches, larches, tulip trees, and birches. Also, hydrangeas are likely suffering a bit because they’re shallow-rooted and therefore drought-sensitive.
• Water container plants more frequently: Container plants can dry out and wilt fairly easily; they should be watered frequently. Taylor says. If plants are in full sun, they likely require more water than containers in shade, which can retain water more easily?

To check the soil’s moisture, either use a soil probe or place your finger in the soil. If it is dry and hard, watering is appropriate. If there is some moisture, continue to monitor the soil’s moisture level.

The Arboretum recommends watering within the drip line of a tree, from the trunk out to the end of the branches, to reach the roots most effectively. The objective is to keep roots moist but not wet. Avoid frequent light watering. Let a hose run slowly at the drip line of the tree, moving it around occasionally. If using a sprinkler system, place a container nearby and let it fill 1-2 inches.

“Gator Bags”–plastic, water-filled vessels that envelope a tree trunk–provide a slow drip to the root system and are a good way to keep your younger tree well watered.

Remember to keep two to four inches layer of organic mulch around a tree to moderate soil temperature and retain moisture. Do not let it touch the trunk or stems.

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