DIY: Insect or Disease Problems Under the Tree Leaf

Put on protective gloves to ensure no problems you find on the tree leaf are spread, and to protect yourself from insect bites.

Lift up the tree leaf carefully, using just two fingers, until you can see the complete underside.

Make a note of the problems you find. The underside of the leaf could be yellowed or have holes. The edges could be jagged, or you might even find brown patches or live insects.

Take a sample of a damaged lead from the tree or insects if you find any. You can opt for a picture if you don't want to disturb the tree or handle insects.

Look over the rest of the tree, including the trunk and branches, for any other signs of damage. Some problems can come with multiple symptoms, not just damage under the leaf. Record all your findings.

Research the tree you're diagnosing to determine the problem and the solution. You can use resources at your local library or the Internet, or take advantage of services offered by a nearby university extension. An arborist or worker at a tree nursery can also assist you. Be sure to take along all the evidence you collected.