Signs of a Declining Tree and What to Do About It

A declining tree usually shows thinning leaves, dead branches in the upper canopy, early leaf drop, or mushrooms and cracks at the base. Many declining trees can be helped if the cause is found early, so have a certified arborist look at it before you spend money on treatment.

What are the warning signs?

• Thinning canopy or smaller, paler leaves than neighboring trees.
• Dieback, meaning dead twigs and branches, especially at the top.
• Mushrooms or shelf fungus at the base or on the trunk, which can signal decay.
• Cracks, cavities or peeling bark.
• Heavy sprouting from the trunk base or along limbs.
• Leaning, or soil lifting on one side of the root zone.

What can cause it?

Common causes include too much or too little water, compacted or disturbed soil from construction, root damage, pests and disease, and storm injury. Fixing the wrong problem wastes time, so identify the cause first.

What should you do first?

1. Take photos now and again in a month, so you can see if it is getting worse.
2. Check watering. Newly planted trees need regular water. Established trees usually need help only in long dry spells.
3. Mulch the root zone 2 to 3 inches deep and keep mulch a few inches off the trunk.
4. Do not pile soil, park or build over the roots.
5. Skip heavy fertilizer unless a test or an arborist recommends it.
6. Do not prune heavily on a stressed tree. Remove only dead and hazardous limbs.

When is it an emergency?

A tree that is leaning toward your house, has large cracks or hanging limbs, or has fungus at the base of a big trunk may fail in the next storm. Keep people and vehicles away from the fall zone and call a professional promptly.

When to call a pro

Our master arborist can assess the tree, explain what is going on in plain language, and tell you whether it needs pruning, treatment or removal. Request an estimate and we will schedule a visit.

Last updated Nov 1, 2026