Cornish tea on the patio

In the Telegraph yesterday, scientist Ken Thompson was talking about why tea bags will help your garden. It’s about composting, and the nutrients they return to the soil, and as you know I’m a big fan of composting.

However, he says this:

“So that the bag will seal properly, it contains a very small quantity of the plastic polypropylene, which melts when heated and so can be used to make a secure seal. But although polypropylene does not break down in the compost heap, it does break up, so it’s hard to find any trace of a tea bag after six months in a compost heap. Moreover the quantity involved is minute compared to other plastic waste, such as carrier bags, plastic packaging.”

So clearly, he’s not worried about adding tea bags to his compost heap, and I wouldn’t imagine too many other people are either. But I am.

I drink a fair amount of tea, and that’s a fair amount of tea bags – the amount of plastic they contain might be ‘minute’, but it will add up. It’s not going to break down in the compost heap, so it’s going to be in the compost I spread on my garden. It’s going to accumulate in the soil. I won’t be able to see it, but it’s there.

And what happens to it then? It’s probably too much to hope that it will just sit there, just slowly building up in the soil. In all likelihood it’s either going to slowly break down (releasing what?) or is going to accumulate in soil microorganisms. We know that microbeads are a problem for ocean life; it seems obvious to me that they’re not going to be any better for soil life.

Are the earthworms in my garden going to get a belly full of plastic bits? Are the birds that eat them going to suffer?


This has been on my mind since 2010, when Which? published a report on the compostability of tea bags. As far as I’m aware, no one has done any work on the topic since. I have been leaving my tea bags out of the compost caddy and putting them in with the food waste, but that seems like avoidance of the problem, rather than a solution. At that time, Garden Organic recommended tearing open used tea bags so you could compost the leaves but bin the bags – they also suggested people should move to using tea leaves.

I’ve always thought that would be a good idea, especially after my research quest confirmed that tea bags are full of dust and aren’t high quality tea. But I never got around to it, even though Ryan bought me a subscription to the Twinings Tea Club for Christmas 2014. All through last year, a new packet of loose leaf tea arrived each month. Most of them are still sealed – last year turned out not to be the right year for that kind of experimentation.

But hopefully this year is. My current tea of choice doesn’t come in a loose leaf format, which is a shame, as it’s a nice everyday tea. I’m going to try and train myself to use some of the tea paraphernalia we have have – we have tea pots, tea strainers and infusers – and remove my reliance on tea bags. I’d like to grow my own teas as well. And learn to cook with tea. So there might be a bit of a tea theme going on here this year.

Or there might not. As you know, I like to keep you guessing πŸ˜‰

Do you confine yourselves to posh tea bags that haven’t been heat sealed? What are your thoughts on the tea bag compost conundrum?