Learn how to use leftover eggshells and coffee grounds to supplement your supply of potting soil! If you’re like me, the thought of lugging home a heavy bag of potting soil from the store is a deterrent and I tend to run out of the stuff, often, especially in the spring. I do have recipes on HomeGrownFun for homemade seed starting mix and potting soil. But what if you specifically have a lot of eggshells and coffee grounds to use up?
Mix half potting soil and half ground eggshells and coffee. Use it like potting soil. It works great for fast growing greens such as arugula. Keep a stash of ground up eggshells and coffee in the freezer. Freezing the material will also help to clean it. Use some in your outdoor planting holes and reserve a portion for your containers. If I’m reusing small nursery containers, I like to add a coffee filter or mesh bag in the bottom to reduce the materials falling through the drainage holes.