HOW TO DIVIDE THEM

1 Lift a clump with a fork and, with a sharp knife, cut pieces of healthy rhizome attached to a fan of leaves.

2 Trim down and tidy the foliage attached to the rhizome section to a fan, leaving around a 20cm-tall section of leaves.

3 This section can then be planted in a hole at soil surface that takes the roots and the rhizome section. It may take more than a year for the new divisions to flower successfully as they’ve been disturbed.