Fern rhizomes which branch frequently can be easily divided. Cut segments from a mature rhizome to include at least one point where frond clusters will originate. Replant divisions at the same depth as the original. If dug in growing season, remove about 1/3 of the foliage to reduce moisture stress.
Fern rhizomes which grow in a single line require a two-stage division technique. First, after carefully removing the surface soil covering the rhizome, cut part way through the rhizome. This injury will stimulate the rhizome to produce a new growth tip. Later in the season, when a new frond has been produced at the injury site, then complete the cutting of the rhizome at the initial cutting location. Lift the severed rhizome and replant it.
Rhizome division should be restricted to ferns growing in home gardens. Fern colonies growing in the wild are easily destroyed by over-zealous division – they should not be disturbed.