In a couple of months time you will all be looking for flowerpots to sow all the tomatos, peppers, courgettes etc and while yoghurt tubs and cut-down bottles are ok, proper flowerpots with carry trays do a better job.
Seek out the local gardening men and tell them you want the pots. Gardeners will now be planting Polyanthus and winter Pansies by the thousand and all the pots and trays will all go in various dustbins. If you have the cheek to ask enough people you get what you want just like Melay Youlay from M.A.S.H.
The best form of recycling is to re-use the item for its designed purpose.
