To propagate Anemonella, the most common method is by root division, which is best done in early spring when the plant is just emerging from dormancy, by carefully digging up the root clump and separating it into smaller sections with a trowel or knife, then replanting each piece immediately in well-drained soil; you can also try propagating from seed, but this may require cold stratification and can take longer to establish new plants. 

Key points about propagating Anemonella:

Best time to divide: Early spring 

Propagation method: Root division 

How to divide: Gently dig up the root clump and use a sharp knife to separate it into sections 

Planting new divisions: Replant immediately in well-drained, moderately moist soil 

Seed propagation: Collect seeds in early summer, allow them to dry, and sow in fall or after cold stratification