Coffee Grounds as Fertilizer
Used coffee grounds for gardening does not end with compost. Many people choose to place coffee grounds straight onto the soil and use it as a fertilizer. The thing to keep in mind is while coffee grounds add nitrogen to your compost, they will not immediately add nitrogen to your soil. The benefit of using coffee grounds as a fertilizer is that it adds organic material to the soil, which improves drainage, water retention and aeration in the soil. The used coffee grounds will also help microorganisms beneficial to plant growth thrive as well as attract earthworms. Many people feel that coffee grounds lower the pH (or raise the acid level) of soil, which is good for acid-loving plants. But this is only true for unwashed coffee grounds. Fresh coffee grounds are acidic. Used coffee grounds are neutral. If you rinse your used coffee grounds, they will have a near-neutral pH of 6.5 and will not affect the acid levels of the soil. To use coffee grounds as fertilizer, work the coffee grounds into the soil around your plants. Leftover diluted coffee works well like this too.
Other Uses for Used Coffee Grounds in Gardens
Coffee grounds can also be used in your garden for other things. Many gardeners like to use used coffee grounds as a mulch for their plants. Other used for coffee grounds include using it to keep slugs and snails away from plants. The theory is that the caffeine in the coffee grounds negatively affects these pests and so they avoid soil where the coffee grounds are found. Some people also claim that coffee grounds on the soil is a cat repellent and will keep cats from using your flower and veggie beds as a litter box. You can also use coffee grounds as worm food if you do vermicomposting with a worm bin. Worms are very fond of coffee grounds.