Many people enjoy a cup of Joe to help get them through the day, but did you know coffee can provide a jolt to your garden as well? Before throwing out your next batch of used grounds, check out the benefits of using coffee grounds in your garden.
Coffee grounds for the compost gardener
For gardeners who make their own compost, used coffee grounds and coffee filters make an excellent source of green compost material.
A good compost pile consists of a 1:4 ratio of green compost material and brown compost material. Green compost material consists of nitrogen-rich organic matter such as eggshells and other food scraps. This must be combined with brown compost material, which includes carbon-rich matter such as dried leaves, twigs, old newspapers and cardboard.
For those who practice vermicomposting, earthworms love coffee grounds, as they provide a gritty substance in their guts to help grind down foods. Use one cup of used coffee grounds per week for a small worm bin. Be careful not to overdo it, as too much can harm the earthworms, and they are essential to the health of your plants and soil structure.
Coffee grounds for garden soil and plants
Both used and fresh coffee grounds contain nitrogen, potassium, phosphorus, and tons of micronutrients, and can be used in your garden as mulch or a slow-release fertilizer.
Adding coffee grounds to soil improves drainage, water retention, and aeration. However, grounds are made up of tiny particles that are prone to clumping, and can therefore block water and other essential nutrients when left right on top of the soil instead of mixed in. When using coffee grounds as mulch, apply it in a thin layer and ideally pair it with compost or other organic matter.
You can apply fresh or used coffee grounds by sprinkling directly onto your soil and mixing it in with your hands, or as a liquid fertilizer, by mixing two cups of used coffee grounds with water in a 5-gallon bucket overnight.
Apply to the soil of acid-loving plants like azaleas, hydrangeas, blueberries, lilies, radishes, and carrots. These not only require nitrogen, phosphorus, and potassium for plant growth, which coffee beans provide, but iron and manganese as well. Sprinkle a teaspoon of cinnamon in this homemade slow-release fertilizer for added essential nutrients.
Keep coffee grounds away from tomatoes and rhododendrons, as they respond poorly to them and may develop brown leaf tips. Also, keep them away from freshly seeded areas, as they can reduce germination.
Coffee grounds for garden pests
While there is no published evidence to support the notion, avid gardeners insist that coffee grounds repel slugs and snails. Simply spread used grounds in a thin layer around vulnerable plants to create a course barrier. This may be unappealing for slugs and snails, as they prefer smoother surfaces.
Additionally, coffee grounds have been effective in keeping cats from using gardens as a litter box. It is not known whether cats have evolved to keep their distance, because of its caffeine content and caffeine’s toxicity to felines, or if the strong smell is what keeps them away. Regardless, it is a quick and easy fix for preventing loss of plants due to the high nitrogen and salt content in cat urine.
FAQ
A: While many gardeners assume coffee grounds are acidic, studies have reported pH levels ranging from mildly acidic to somewhat alkaline.
A: Yes, when used properly, coffee grounds provide essential nutrients which aid in plant growth.
The final word
The benefits of using coffee grounds outweigh any drawbacks. Just be careful to add an appropriate amount to your soil or compost and keep it away from sensitive plants and seedlings. And, as always, reach out to your local Lawn Love lawn care professional to assist with any gardening needs.
