By: Lisa Kaplan Gordon
Learn to spot a tree under stress, and you may be able to nurse it back to health.
When it comes to landscape love, there’s nothing sadder than losing a tree to a storm, drought, or disease.
You can’t save every sick tree: sometimes a tree dies before you even know it’s unwell. Sandra Dark, author of Weatherproofing Your Landscape, says trees that don’t leaf out in spring are probably beyond help. Time to continue the circle of life, grind them up, and turn them into garden mulch.
But if you recognize the early signs of tree stress, you may be able to help your tree before it’s too late.
Healthy foliage for most trees is bright green. If leaves turn yellow or brown, it means the tree’s root system has been damaged, usually from drought or flooding.
Drought: Run a soaker hose around the tree, starting 1 foot from the trunk and extending to the end of the drip zone — the outer edge of the tree’s leaf canopy. Give the tree 10 gallons of water for every inch of trunk diameter, or about 45 minutes of soaker hose watering. Repeat 2-3 times a month, depending on rainfall.
Flood: After a flood, watch your trees carefully — signs of stress from damage and too much water may take two or three weeks to appear. When the water recedes, prune damaged limbs, making clean cuts. Perform a soil test to determine mineral levels, then add only the nutrients that are lacking.
Oozing through bark
Oozing or bleeding bark can be a sign of fungal infection or insect infestation. Sometimes, a tree with a healthy immune system will heal itself; sometimes the tree is too weak and needs the help of a certified arborist.
Get to know an arborist
Trees contribute to your home’s curb appeal, so it pays to establish a relationship with a certified arborist who will help you identify problems, stop disease from spreading, and preserve your property’s value.
Each spring, ask the arborist to inspect your trees to check for beginning problems, such as flaking bark, strange growths, and brittle branches.
A certified arborist can also:
- Suggest appropriate pruning to keep trees healthy and looking good.
- Brace trees for added support.
- Spray trees to protect against insect infestation.
- Identify trees that are in danger of falling, obstructing wires, or crowding and causing harm to other trees.
- Recommend trees that should thrive in your yard.
Cooperative extension help
Many state cooperative extensions can help you diagnose what’s wrong with your trees based on pictures, or samples of leaves, bark, and insects.
- The University of Missouri Extension has an “Ask An Expert” feature on its website.
- You can submit a sample to the Iowa State University Extension and Outreach, which will diagnose your tree’s problem for $10-$20.