We try hard not to waste plastic in the nursery. Some plug plants already come in returnable rays. The non-returnables get used and re-used on the nursery for our own propagating until they finally fall to bits.
We are always happy to take back any pots and trays that come from us; they do not need to be washed, just emptied please. But we cannot accept random-sized pots from elsewhere; we have no use for them and have to pay to have them disposed of! Oh, and please do not leave the pots in your shed gathering snails before bringing them to us – we have plenty of our own! See our pictures of good and bad pots!