If you're a keen gardener, you've probably heard the rumours about using coffee grounds as organic fertiliser.
A much-touted tip, one that often makes the rounds online at this time of the year, there's something in it.
The nitrogen in the coffee can help lots of plants, as gardeners can attest to. But not all plants will benefit, meaning green-fingered amateurs risk doing more harm than good if they use the hack without following instructions.
