Which bin for plastic plant pots?
Usual answer in the UK
Take-back Shop or take-back point
Many garden centres take back plastic plant pots. Some councils accept them in mixed recycling; check first.
Also possible: Mixed recycling bin; General waste bin.
Does every council do this?
Most councils follow the answer above, but bins and sorting rules are set locally, and a few councils still do things differently. If your bin has a sticker, or your council sent a leaflet, follow that. Enter your postcode to go straight to your council's guidance.