Do some of your grasses have an empty, dead centre? That tells you it’s time to divide them, before they start to grow vigorously. Cut the foliage back to 10 to 15 centimetres, then dig up the entire clump. Use a large knife or sharp spade to cut it in half and then quarters. Remove all the dead or diseased parts, making sure the remaining divisions have good roots still attached, Compost the dead material and replant the divisions, watering well and mulching.
