Tree health troubleshooting guidelines (adapted from Johnson et al., 2008).
Link to this table

If you see: Potential cause: You should:
A flat-sided trunk at the base of the tree Encircling root restriciting the flow of water and nutrients between the roots and rest of the tree Excavate to check for encircling root
Bark damage near the bottom of the tree Rodent or string trimmer Apply mulch/trunk guard to protect from further damage
An elm tree with liquid oozing from the trunk Slime flux or wetwood Not worry about health
An elm tree with bright yellow leaves on one or two branches Dutch elm disease Immediately call the university* or an arborist
Webs in the branches or webs covering the tips of branches Fall webworm or Eastern tent caterpillar Not worry about health
Many branch tips snipped off and laying on the ground Squirrel damage Not worry about health
Black clumps on branches of a cherry tree Black knot Call for advice*
Very little growth Many Call for advice*
Hole in trunk or branches Many Call for advice*
Leaves sticky and covered with a black velvety coating (like soot) Piercing, sucking insect and sooty mold Hose down leaves to get rid of sap
Leaves wilted Many Call for advice*
Spots on leaves Many Call for advice*
Small leaves Many Call for advice*
Sparse leaves Many Call for advice*
Yellow or brown leaves Many Call for advice*
Holes in leaves Insect feeding Not worry about health
Bumps on leaves Many Not worry about health
*Call an arborist or other qualified professional

This page was last edited on 7 August 2022, at 16:50.