Originally Posted by StuckInYYZ

I mix crushed egg shells (air dry them and a quick run through a pestle and mortar) with the coffee grinds and sprinkle it in my garden. It cuts down on the acidity a bit and the plants seem to like it. The filters get air dried and tossed into the green bin. Interestingly enough, the tomatoes and raspberries seem to like the mixture a lot as the plants grow back bigger every year.