If planting Tiger Grass as a screen, ideal spacing is 1 to 1.5m apart, and atleast half a meter away from fence, building, etc.

After 4 or 5 years, there is often a lot of old dead growth in the centre of the clumps. This can either by cut out one stem at a time with secateurs, which is a very time consuming process, or alternatively cut the whole clump down to ground level (ie cutting off all growth just above ground level). This is best done with large hedging shears, hand saw or chainsaw. If this is done late winter / early spring, then the new growth will grow up to near full height within a few months.