Are you a coffee drinker? Don’t throw the grounds away if your a gardener! - You may have a need for them after all. 1.Repel ants, snails and slugs by sprinkling coffee grounds near the point of entry, or around the planter base. 2.Deter cats from your garden, by sprinkling around garden and planter base. 3.of course you can use them in compost! 4.and as a fertilizer for acid loving plants like tomatoes.