7 Clever Uses for Tea Bags Fertilize PlantsUsed tea bags (especially compostable ones) nourish soil. Roses, houseplants, and ferns love the nutrients. Soothe SunburnsCold black tea bags can relieve sunburns thanks to tannic acid, which cools and heals the skin. Relieve Minor BurnsApply a cool black tea bag to minor burns—the tannins help reduce pain and inflammation. Remove WartsPlace a...