Perhaps we should start by putting 'Re-use or return' stickers on black pots. GC's and nurseries should be made to accept black pots back so they can be washed and re-used. Surely it would save them money long term?
Coir has been mentioned, but with a figure of 500,000,000 pots and bedding trays used every year in the UK alone, I can't see that being a viable option. Imagine how much coir would have to be shipped half way across the planet every year to sustain that amount, and would there actually be enough coir to cope that demand? Assuming it's not just us Brits who want an alternative to plastic pots , I can't see coir being answer.
This has been a laudable thread, gardeners on the whole are people that want to improve the planet and there are many examples of us trying to do so.However, it is naive in the extreme, to believe that we can just abandon the use of plastic in the garden.Many alternatives come with their own problems, some of which are equally detrimental to the health of the planet.It is fantastic that we are talking about the problem, but to retain credibility, we should not talk about banning the use of plastic, before we have properly looked at the alternatives.