We’re a nation of coffee lovers, but can we — and should we — spare a cup for our gardens? The effects of spreading coffee grounds in our gardens to try and boost plant growth is well-discussed, but with lots of conflicting information out there, it can be difficult to know whether it’s worth it at all. Thankfully, compost and lawn dressing retailer Compost Direct has researched the topic to help you make a decision.
What are the benefits of using coffee in my garden?
Although research is yet to be carried out to determine the exact benefits of using coffee grounds in your garden, there are many supposed bonuses. Coffee grounds are a source of fatty acids, essential oils and nutrients that can help enrich the soil, providing the nutrients and minerals required for healthy plant growth.
As the coffee grounds decompose, they release even more nutrients into the soil, including vital nitrogen, potassium and phosphorous. This is especially beneficial for nitrogen-loving plants, such as leafy vegetables and flowers like roses, azaleas and rhododendrons.
The structure of the coffee grounds is also beneficial, as it aids soil drainage, while some report that it actually acts as a deterrent for garden pests, helping to ensure the quality of your plants.
Of course, these benefits are largely unconfirmed, as there has been limited research into the full effects. However, many gardeners swear by using grounds in their garden.
How can I use coffee in my garden?
If you want to experiment with using coffee grounds in your garden, there are a few ways to do it; either by adding it direct to your soil, using it as a mulch or by adding it to your compost.
Adding coffee grounds to soil
You can add the coffee grounds direct to the soil to act as a fertiliser. This will help to add organic matter direct to your soil. Many people believe that adding coffee grounds to your soil will alter its pH. However, it’s only fresh coffee grounds that will do so, as they are acidic. Once you wash them, or turn them into a cup of coffee, their pH changes to around neutral, so will have a minimal impact on the acidity of your soil.
Coffee grounds as a mulch
Coffee grounds can be used as a mulch for your soil, although using too much can prevent the movement of moisture and air. If you do plan on using it as a mulch, it’s advised that you only use around half an inch of coffee grounds along with an organic mulch.
Adding it to you compost
Coffee grounds are nitrogen-rich, so they make a great addition to compost. However, if you do plan on adding them to your compost bin, you’ll need to get the ratios right. Around 10 to 20 percent coffee is the most desirable amount alongside leaves and fresh grass clippings. Over 30% coffee could impact the overall quality of the compost, so always make sure you get the correct balance.