Should you use coffee grounds and tea leaves as fertiliser for your garden?

In terms of soil pH, both coffee grounds and tea leaves are mildly acidic. Photo: 123rf.com

Some gardeners swear by them; they say spent coffee grounds and tea leaves should be reused as fertilisers or added to compost heap. They are often touted as green, eco-friendly options for garden fertilisers because of their nutrient content and potential benefits for soil health. These organic materials are abundant and contain nutrients that are important for plant growth.

Spent coffee grounds contain approximately 2% nitrogen (N), 0.1% phosphorus (P), 0.3% potassium (K), 0.2% calcium (Ca), and 1.9% magnesium (Mg). Spent tea leaves offer an even richer source of nutrients: 4% N, 0.2% P, 1.3% K, 0.7% Ca, and 3% Mg. These values compare favourably with those of other organic waste products traditionally used in composting and soil amendment.