Pruning Pampas grass is quite a process but worth doing, and it is best to do it now in the growing season. You need first to cut it right back to about two foot using very sharp shears or better still, an electric hedge-cutter. Do make sure you wear protective clothing. The grass is razor sharp, so wear very thick gloves and keep children and pets away. The base of the plant will be full of dead leaves and matted material, which should get burnt out. The best way of doing this is to make a bonfire elsewhere and take embers or hot ash from this and put it on the plant. Your ‘fire’ should only burn for two or three minutes, otherwise it could damage the roots. Have a hose handy. After this, it would be worth dividing it up. You can do this with a very sharp-edged spade, but it is hard labour. The GardenadviceTeam, usually dig it up, cut it into quarters with a woodcutting saw and then they replant it. It will take a whole season to get going again, but the plant will benefit and put on good growth and produce better plumes in the following season.