Why Is My Mature Oak Tree Shedding Leaves and Acorns Excessively?

A homeowner noticed their large, mature oak tree dropping green leaves with round brown spots and wilting, along with a heavy acorn drop over the past week. They asked for a diagnosis.

Possible Causes of Oak Decline

Without seeing the tree, pinpointing the exact issue is difficult. However, in regions like New Jersey, oaks commonly decline or die suddenly due to several factors:

• Drought stress from current and previous dry years.
• Bacterial Leaf Scorch, a vascular disease that causes leaf browning and early drop.
• Two-lined Chestnut Borer, an insect that attacks stressed oaks.
• Armillaria Root Rot and Phytophthora, fungal diseases affecting roots and lower trunk.
• Sudden Oak Death (primarily west of the Mississippi River).

Recommended Action

Because symptoms overlap, the best course is to hire a Certified Arborist for an on-site evaluation. They can identify the specific problem and recommend targeted treatment or management strategies.