A keen gardener has urged people not to throw away one leftover food item as it could be the key to optimising your soil’s health this spring. The Container Gardener on TikTok has suggested people reuse their old coffee grounds in the garden as a natural fertiliser alternative.

Not only can it help promote soil health, but it can also be used as a deterrent for slugs, too. Instead of throwing away the used coffee grounds, bag them up and save them for a later date to use in the garden. The Container Gardener said: “The nutrients contained in coffee grounds will be recycled back into the soil when finished compost is used as a mulch or dug into the soil. Also, add any un-drunk coffee to dry material in a compost bin.”

How to use coffee grounds on plants

You can add the coffee grounds directly on the plants that need fertiliser, simply by adding them to the plant pots or the soil bed. However the grounds should be used in moderation.

Gardeners World also stood behind using coffee grounds as a fertiliser for plants. This is because the grounds contain a number of nutrients which are useful for soil health and for plants to grow.

Coffee grounds contain high levels of nitrogen, as well as potassium and phosphorus. Oxford Garden Design explained that plants which love acidity are the best ones to use coffee grounds for.

These plants include azaleas, rhododendrons, camellias, hydrangeas (blue varieties) and Pieris (Japanese Andromeda).

As coffee grounds are rich in nitrogen, they help to promote lush leaf growth, so can be used on leafy vegetables spinach, lettuce, kale, and Swiss chard.

However it’s good to remember which plants and vegetables don’t like coffee grounds. You should avoid putting them on the likes of tomatoes, lavender, rosemary, succulents and cacti, and clovers and legumes.

You can also compost using coffee too. Gardeners World explained that you can mix the grounds with dry and “woody” waster to help speed up the composting process.

It’s important to get a balance between ‘wet’ and ‘dry’ materials.

They explained: “The nutrients contained in coffee grounds will be recycled back into the soil when finished compost is used as a mulch or dug into the soil. Also, add any un-drunk coffee to dry material in a compost bin.”

When it comes to repelling slugs, Greenside Up explained that slugs and snails don’t like the smell of coffee. If you’re adding the ground directly onto the plants, you can mix a solution of cold, strong coffee and spray them onto the pests.

Gardeners World added that the grounds can be used around slugs’ favourite plant - like hostas - but explained that the results aren’t guaranteed.