Oak Pellet Droppings: Immature Acorns and Tannin Stains

Oak dropping small pellets overnight; soften and stain concrete when raining. Heavy rain = more pellets.

Identity: Aborted First-Year Acorns

Acorns take 2 years to mature. Weather stress causes early abort. High tannins (like red wine) stain porous concrete dark with green/gold cast.

Stain Removal

• CLR (calcium-lime-rust remover) with warm water, brush.
• Muriatic acid (1:20 with water, add acid to water). PPE required. Bubbles on concrete. Rinse thoroughly.

Test small area first.