I recently removed a tall oak tree near my home. Other than renting a stump grinder, how can I eliminate the remaining trunk near the ground?
All stumps rot in time. You might consider using the stump as a spot to set a birdbath or even a container garden until it naturally declines. If you want to speed decomposition, try drilling numerous holes in the trunk and packing them with soil. Keep the trunk moist, and the microorganisms in the soil will help the trunk to rot. The process still takes time.