Hackberry Trunk Fungus: Decay vs. Root Rot—How to Tell

Question: White, easily removable fungus at base of huge hackberry for two years. Takes some bark with it. Is it treatable or should the tree be removed?

Answer

Two possibilities:

Decay Fungus (Most Likely if Canopy Is Full)

Attacks dead heartwood only. Tree survives for decades, slowly hollowing. Hazard only if large limbs break and are hollow.

Root Rot Fungus (If Canopy Is Sparse/Yellow)

Attacks living roots, causing progressive dieback over years.

Action Plan

1. Observe foliage after full leaf-out: green and dense = decay fungus; thin and pale = root rot.
2. Either way, fertilize with 10-10-10 at 1 lb per inch trunk diameter to strengthen the tree.
3. For definitive diagnosis, contact your state forestry agency (often free) or a certified arborist.

Don't panic—both progress slowly. Informed monitoring is key.