Snip off the top 8 to 12 inches from your Pieris japonica 'Fire n Ice' and that will encourage side branching. Make the cuts just above a joint or node as that is the spot where the new sprouts will form. The best time to prune is right after the shrub finishes flowering in the spring. Get snippy each spring until you get the shape you are after. Keep growing, Marianne Binetti