Mountain ash (Sorbus spp.) is a year-round thriller that thrives in clay. Its white flowers in the spring and early summer give way to orange or red berries that stand out against dark-green foliage.

Cankers can also develop on the trunk." Apples are the primary hosts, but pears and Sorbus species are also susceptible, as are ash, beech, and some other trees less frequently. If you discover a ...