Keep egg shells in open container in fridge. When the container is full, crush shells into small bits and sprinkle them around base of your plants. Sharp eggshells will deter slugs, snails other bugs & adds touch of calcium to soil.
Aspirin is a remedy for fungal plant problems (black spot, powdery mildew, and rust are a terrible trio of fungi). Dissolve two uncoated aspirin tablets milligrams each) in 1 quart of water and use as a foliar spray to thwart these diseases.