What Does Coffee Grounds Do For Indoor Plants. Coffee grounds in your potting soil can ward off indoor pets like cats also help reverse leaf browning on peace lilies. Half a cup of coffee grounds mixed in a gallon of water makes a great liquid fertilizer for your plants whether they grow in the garden or in pots.
Some even suggest using coffee as a mulch. Coffee grounds ward off slugs. Nitrogen is one of the significant components in chlorophyll and is essential for photosynthesis.
Primarily as a fertilizer due to their high nutrient content.
I would have a couple worries using coffee grounds directly on house plants. Coffee grounds ward off slugs. That makes them a great choice for a slow-release fertilizer on some species of houseplants. Grow HUGE plants with coffee grounds.