I'm hoping to make a miniature tufa garden, suitable for AGS /SRGC shows. Would readers recommend a single piece of tufa, as per my photograph, or multiple pieces of tufa to create more crevices? Would a single piece need cementing to the base of the pot?. also the best method of watering the plants in the tufa, do you water from the top and the water percolate downwards or water individual plants?