To raise beautiful flowers, tasty vegetables and healthy plants, gardeners have all matter of solutions, including the liberal use of coffee grounds. High in nitrogen, old coffee grounds provide plants with nutrients and attract helpful creatures like earthworms while deterring destructive pests. Best of all, coffee grounds are all natural, and many coffee shops give them away for free.
To get big, juicy tomatoes, gardeners can use old coffee grounds as a fertilizer. Coffee grounds are rich in nitrogen and have a slightly acidic quality, which help soil to create natural strains of bacteria that are beneficial to the plants. The grounds also supply tomatoes with a steady diet of nitrogen, which they require to thrive. Though commercial nitrogen fertilizers are available, coffee grounds are an natural option, something worth considering when growing vegetables for human consumption.
Many gardeners take pride in their ability to grow roses that burst with color and fragrance and the process is made all the easier and even less expensive by using coffee grounds as a fertilizer. Bella Online explains that roses need nutrient-rich soil to grow, though making or purchasing the needed compost can be expensive and time-consuming. However, used coffee grounds infuse the ground with nitrogen, making it well-suited for rose bushes and worms attracted by coffee grounds; and they further aerate the soil, making it better for growing.
Flowers that bloom in the spring from bulbs, like tulips and daffodils, can benefit from a dose of coffee grounds in more ways than one. Like tomatoes and other plants, such flowers will thrive from an extra dose of nitrogen and other nutrients that grounds release into the soil. Perhaps more importantly, coffee grounds are also a way to protect spring flowers from predators like slugs without resorting to harsh chemicals. When crawling over coffee grounds, slugs absorb the caffeine contained therein, which poisons them and prevents them from destroying gardens.
Rhododendrons, like tomatoes and marigolds, love acidic soil and can benefit from a sprinkling of coffee grounds, which raise acid content, making the ground more amenable to the plant's needs. Coffee grounds also help to protect rhododendron bushes from root weevils. A layer of grounds around the base of a rhododendron shrub will deter the pests, though regular application is necessary to keep the weevils at bay.