Dealing with Foul-Smelling Water on Freshly Ground Pecan and Oak Stumps

Cause of "Black Water" on Ground Stumps

After grinding large pecan and water oak stumps (60–70 years old), rain can cause a sewage-like smell from fermenting sap and wood compounds. This "black water" is pumped by still-living roots trying to send nutrients to the crown. Pecan tends to smell stronger than oak due to different wood chemistry.

Solution

• Apply powdered lime (¼ inch layer) to stump surfaces to neutralize acidic odors.
• Expect the smell to stop within weeks as root activity ceases.
• Oak stumps may follow suit but typically with less odor.

Key Takeaway

Post-grinding stump odor is temporary and species-dependent. Lime application is a simple, effective remedy.