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Coffee as Fertilizer

A hot cup of morning coffee can be just the thing to jump start your energy, but coffee is also a valuable jump start for the garden. Read on to learn how to use this household item as a fertilizer for your garden.

A hot cup of morning coffee can be just the thing to jump start your energy, but coffee is also a valuable jump start for the garden. Read on to learn how to use this household item as a fertilizer for your garden. The coffee grounds leftover from brewing your morning joe are a rich source of nitrogen. Research has shown that coffee grounds are about 2% nitrogen by volume, making them a great source of nitrogen for the compost pile. And, since they won’t contain any parasites, coffee grounds are often suggested as a safe alternative to manure in compost piles.

While some gardeners do spread coffee grounds directly on the soil at the base of plants, some studies have shown that using uncomposted coffee ground can actually stunt plant growth. While grounds contain plenty of nitrogen, microorganisms need to break down the grounds to release it. If using coffee grounds directly in the garden, be sure to mix them with soil before spreading. The best option is to add grounds to the compost bin (as a “green” material, despite their color.) The added nitrogen will help increase the compost pile’s temperature, improving decomposition.

Coffee grounds are not the only way to use coffee in the garden or compost heap. Brewed coffee can also have benefits. Coffee grounds have a nearly neutral pH of 6.5- 6.8 (neutral is 7), but brewed coffee reportedly has a lower pH, ranging around 5.2 to 6.9 depending on the type of coffee and its strength. Lower pH levels are more acidic, and plants generally prefer to be on the acidic side of neutral. Occasionally pouring leftover brewed coffee on the soil can help lower pH, but be sure to measure soil pH levels to ensure that they don’t fall below about 5.7. In addition, brewed coffee contains magnesium and potassium, which are necessary plant nutrients.

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