Gardeners are being urged to stop throwing away coffee grounds, as the experts at BBC Gardeners' World Magazine highlight their value as a natural fertiliser. With around two billion cups of coffee brewed daily worldwide, according to the British Coffee Association, the used grounds can be put to good use in the garden rather than being discarded in food waste bins or down the drain.
According to the gardening experts, coffee grounds are rich in nitrogen, potassium, and phosphorus, making them an excellent compost ingredient. They can be applied directly to the soil around most plants if used with care and moderation. The grounds break down easily and enrich compost, improving soil structure and plant health.
For best results, the experts recommend mixing used coffee grounds into a compost bin or worm bin. If applying directly to the soil, sprinkle them lightly around plants, avoiding thick layers that can block air and water. It is also advised to rotate the application spots to prevent overuse in one area.
However, caution is needed. Coffee grounds are slightly acidic, making them suitable for acid-loving plants like hydrangeas and nutrient-hungry plants like roses, but they should be used in moderation. They can also act as a natural slug deterrent, though results vary. Caffeine residues may stunt the growth of some plants, such as tomatoes, and interfere with seed germination.
Importantly, coffee grounds are toxic to dogs, so gardeners with pets should avoid using them in areas accessible to their four-legged friends.
