During early spring growth, it is difficult to distinguish the interrupted fern from the cinnamon fern unless there are fronds left over from the previous year. Both have woody bases and large, pale green fronds. It is one of the earliest ferns to emerge in the spring, arising from a white, cottony ball that was formed the previous fall. As the plant grows, the fertile leaflets appear in the middle of the frond (giving the plant its “interrupted” name). Once the spores mature, the fertile parts wither and fall off, leaving an empty area in the middle of each frond.
Like all the ferns, interrupted ferns can be grown from spores, but it is much easier to transplant them, using the same cautions as described for previous ferns. Neither the interrupted nor the cinnamon spread as rapidly as the ostrich fern, but as a plant matures and dies out, a circle of young ones have usually grown up around it. Some of these offspring can be carefully removed.
This fern can often be seen growing with the cinnamon fern. It tolerates much the same conditions, preferring shaded woodlands with moist, rich soil. The interrupted fern does not establish itself quickly, so if habitat is destroyed, it will be slow to return. That’s why some judicious transplanting can be useful to help it return to an area.