I use a 3 parts sand , 1 part sieved peat moss and 1 part cement mixture .
It's hard to find Perlite here and it's expensive € 10 for a small bag . Cement is €5 for a bag I can barely lift and the sand is almost free so no hypertufa for me .
I think the addition of the peat helps with darkening the colour of the trough and also helps neutralise the alkaline in the cement making the mosses grow sooner . I'm trying to make the optimum size planter that's portable and doesn't require a gorilla to move it around . One earlier model I made is permanently at the back of my house unless I can borrow a helicopter to winch it out !!
