Epsom salt is familiar to gardeners as a fertilizer. When you find your plants looking tired, giving them a small dose of Epsom salt is a quick way to rejuvenate them. This is particularly true for ferns and palms. Roses, azaleas, tomatoes, peppers, and fruit trees also respond well to its regular application with increased flowering and yield. If that’s not enough, this inexpensive non-toxic solution can help keep pests out of your garden, too.