Coffee grounds are commonly used to help fertilise plants, helping them to thrive. They can help to improve soil structure and deter certain pests. However, according to an expert, there are only three types of plants which should be fed coffee, and the rest of your garden should be left untouched.
Jack Stooks, former royal gardener, said: “Coffee is acidic, so it’s really only suitable for certain types of plants. Specifically, rhododendrons, azaleas and hydrangeas.
“These plants prefer acidic soil, so they’ll tolerate the coffee grounds well.”
But for the rest of the plants in your garden, the expert said this type of fertiliser isn’t ideal.
Gardeners should avoid going overboard with coffee grounds on plants that don’t favour acidic conditions.
The expert added: “Most garden soil can handle small amounts just fine, but if you’re applying large quantities, definitely stick to acid-loving plants. Otherwise, you’re better off disposing of the grounds in the compost.
“In short, if you are unsure about the plant, the safest way to use it in the garden is in compost.
“It’s reliable, it helps the composting process, and you don’t have to worry about it affecting plant health in unintended ways.”
For example. Some plants which will not benefit from coffee grounds include lavender, rosemary, thyme and other Mediterranean herbs.
Certain flowering annuals, such as geraniums and petunias, may also struggle with coffee grounds.
Tomatoes, while sometimes benefit from diluted coffee, can be negatively affected by large amounts of fresh grounds.