Coffee Grounds And Eggshells For Indoor Plants. Of course it does mean that it can be difficult keeping your plants healthy especially when it comes to introducing nutrients to their soil. It will kill the seedlings.
Directly applying coffee grounds to indoor plant soil can cause excessive moisture retention fungal overgrowth and even impair plant growth. Adding used coffee grounds will NOT acidify the soil at all since the acid is washed out of the grounds in the coffee making process. We are advised to put them in the garden for perky plants and bright blue azaleas.
Coffee grounds ward off slugs.
Each type of plant will prefer a different amount of coffee so start small by adding 1 tablespoon of coffee grounds around each plant lightly working it into the soil once a week. The coffee grounds can also be used as an organic matter. Coffee grounds wont provide a burst of nitrogen to houseplants or garden plants immediately. This is an urban legend and an old wives tale.