Don’t throw away those coffee grounds! Acid-loving plants need their coffee too. Use a thin layer around roses, rhododendrons, azaleas, camellias, and heather for great blooms. Coffee grounds also repel slugs and snails because they hate the hyper feeling. Some trees also enjoy the jolt such as cedars, hemlock, and spruce. Unless you have acid-loving vegetables, I wouldn’t recommend coffee in the garden.