* Healthy leaves: Leaves are full-sized and well-developed.

* Unhealthy leaves: Leaves are small, stunted, or misshapen.

Leaf color:

* Healthy leaves: Leaves are green and vibrant.

* Unhealthy leaves: Leaves are yellow, brown, or wilted.

Leaf edges:

* Healthy leaves: Leaf edges are smooth and even.

* Unhealthy leaves: Leaf edges are jagged, torn, or curled.

Leaf veins:

* Healthy leaves: Leaf veins are visible but not prominent.

* Unhealthy leaves: Leaf veins are swollen or discolored.

Leaf surface:

* Healthy leaves: Leaf surfaces are smooth and shiny.

* Unhealthy leaves: Leaf surfaces are dull, rough, or scaly.

Leaf spots:

* Healthy leaves: Leaves may have a few small, light-colored spots.

* Unhealthy leaves: Leaves have many large, dark-colored spots.

Leaf drop:

* Healthy trees: Trees may lose a few leaves in the fall.

* Unhealthy trees: Trees lose leaves excessively throughout the year.

If you notice any of these signs of ill health in your urban trees, it is important to contact a certified arborist for further evaluation.