Hi,
I had a behind-the-scenes tour of a local plant nursery today. What was interesting is that they say they grow all their own bedding plants but most of them are bought as plugs from Holland and then they pot them on at the nursery. The plantsman said 90% of nurseries in the UK do this. So I asked what happens to all the module trays that the plants come in. He said they use some for cuttings and recycle the rest – I asked if I could have a few and they gave me some. The standard seems to be 2cm plugs in 77s, so quite large trays but I can cut them into smaller sections to fit on my window sills. They are quite sturdy and if they break after a couple of years I’ll just go back and ask for a few more. Worth asking at your local nursery if they have any spare.