20. Sep, 2018

Composting Tea Leaves

In recent months there has been much criticism of the use of plastic in teabags and the advice given is that where possible use loose tea, just in case the publicity has led to some deciding it is not worth the bother of composting tea. It is worth reemphasising just how good used tea can be as a nutrient for the garden. Lawrence Hills in Grow Your Own Fruit and Vegetables, first published in 1971 by Faber and Faber, made the case for adding tea to the compost heap and nothing has changed apart from the fact that if tea bags are composted they should either be plastic free, be torn open and emptied or the remains of plastic bags rescued after composting.

As with other kitchen waste it is best to collect the cooled tea leaves (or bags) after each pot or mug of tea, in a kitchen caddy along with other vegetable waste and only make the trip to the compost bin or worry when the caddy is full.

The leaves contain about half as much nitrogen as dried blood and more than poultry manure. Tea leaves contain approximately 4.4% nitrogen, along with, 0.24% phosphorus and 0.25% potassium the addition of tea to the compost heap will provide nutrients encouraging the decomposition process. All teas are not the same each variety of tea, black, green or red, will contain a different ratio of compounds but whichever you prefer they will make a useful addition to the compost bin particularly if collected in larger quantities from a local tea shop or café.

Tea leaves, and tea bags, can be added direct to the soil tea as mulch on the soil surface round the plants or to dig the leaves into the soil when preparing the plot. However, as a composter I would recommend composting rather than direct application as it saves time to treat the tea as any other compostable kitchen waste. One of the disadvantages in direct application is that the Tannic acid is in the tea can in some soils lower the pH, so it would be advisable to check the soil pH before the addition of tea leaves.