With a recent rise of new gardeners across the UK, largely brought on by the pandemic, you may be spending more time in your garden this summer. If you’re a coffee drinker and new gardener, don’t throw away your used coffee grounds – they can serve a useful purpose.
Coffee grounds have numerous uses in the garden. They can be used for composting, as fertiliser and even for the removal of pests and weeds! Here are some of the creative ways to get more out of your waste coffee grounds in the garden.
Composting your coffee grounds
Composting coffee is a great alternative for something that would’ve otherwise ended up in landfill. Composting your coffee grounds helps to add nitrogen to your compost pile, in turn adding balance and warmth to your compile pile, speeding up the decomposition process.
If you’re adding coffee grounds to your compost, remember it’s considered green compost material and will need to be balanced with the addition of brown compost material.
Using coffee grounds as fertiliser
Some gardeners have experimented with adding waste coffee grounds directly onto the soil, as a fertiliser. Whilst coffee grounds add nitrogen to your compost, they won’t immediately add nitrogen to your soil. Despite this, coffee grounds are rich in other nutrients, such as potassium and phosphorous.
Another benefit of using coffee grounds as a fertiliser is that is adds organic material to the soil, which improves drainage, water retention and aeration of the soil. Used coffee grounds also provide nutrients to microorganisms, promoting plant growth.
The acidity of coffee
If you’ve got this far in the article, you probably have some doubts over the acidic content of coffee. Due to their acidity, its true that coffee grounds (especially if they’re fresh), can change the pH composition of the soil. However, used coffee grounds, more so if they’re rinsed, will tend to have a neutral pH of 6.5-7, meaning they won’t have an effect on the acidity of the soil.
That being said, time should be taken to match your coffee grounds with plants that prefer more acidic soil. This tends to be blue flowers, such as French hydrangeas and Lace caps, as the pH of the soil leads to bolder and brighter blues.
Alternative uses for used coffee grounds
Used coffee grounds make up for a variety of other uses around your garden including:
- Used coffee grounds are great as a mulch for plants.
- Other uses for coffee grounds include keeping slugs and snails away from plants. The caffeine in the coffee grounds repels pests away from your beloved plants.
- Used coffee grounds are also great to use as worm food if you do vermicomposting. Worms are very fond of coffee grounds and they help in your garden too.
Alternative uses for fresh coffee grounds
As fresh coffee changes acidity of plant soil, you have to make sure you use it in the correct areas of your garden. Here are some ways fresh coffee can benefit your garden:
- Use fresh coffee grounds on acid-loving plants such as azaleas, hydrangeas, blueberries and lilies. Some vegetables also like acidic soil, such as radishes and carrots.
- The use of fresh coffee grounds can also help suppress some types of weeds. They also help to suppress fungal pathogens from your garden.
- Sprinkling dry, fresh grounds can help deter pests. It doesn’t fully eliminate them, but it’s an eco-friendlier alternative to keeping pests, cats, rabbits and slugs away from your plants.