Ah, moss! I have a strange story about moss. Not in my own garden where it grows beautifully and is allowed to but in the Bristol Botanic garden where we want it at the beginning of the evolutionary dell it being related to the first landplants that evolved, 500mya. We have collected it from nearby woods; we have planted it; we have watered it; we have concluded that a combination of circumstances are against us - large trees roots keeping it too dry: being on a hill the water drains away too quickly; drought at the wrong time of year for moss. Whatever it is, the moss will not grow for us. But we keep on trying. I get lots of moss in my garden by just leaving rotting logs in a damp place, The north facing side then grows lovely moss. with primulas seeding themselves happily in front of the log what prettier sight could you have? See photo on Forum "Plants"