Answer: Ornamental grasses can usually be left in place for three to five years before they need to be divided. They need it when they begin to go bare in the center of the clump, the roots begin to form a sort of donut shape. This is similar to other perennials that need division to help keep them growing vigorously; you would dig it up by the roots and cut it into sections or divisions. Discard the tired center portion of the plant and keep pieces of the strong new outer growth. The larger the division, the sooner you will have a large plant. Do this in the spring just as it starts to grow for the year. I hope this help.
Q&A Library Searching Tips