Cystopteris spp.
fragile ferns
Temperate and montane Northern Hemisphere
Overview
Cystopteris spp. is a genus of around 30 species of small, delicate ferns in the family Cystopteridaceae, found in temperate and mountainous regions across the Northern Hemisphere and beyond. Plants form low tufts or spreading patches of finely divided fronds 4-18 inches (10-45 cm) long, arising from slender creeping or short-erect rhizomes. The fronds are thin-textured and twice or three times divided, carried on brittle stalks that snap easily, which gives the group the name fragile ferns. On the underside of the fronds the spore clusters are covered by a hood- or bladder-like flap, the source of the alternative name bladder fern. The fronds are deciduous, dying back in late summer or autumn and in dry sites often withering earlier in summer. Most species grow in cool, moist, shaded places on rock ledges, cliff crevices, walls, and the floor of damp woodland, usually where drainage is good. They tend to be short-lived in cultivation unless the cool, moist, rocky conditions of their habitat are matched. The finely divided, lacy fronds suit shaded rock gardens and crevice plantings rather than open borders.
Native Range
Cystopteris spp. is widespread across the temperate and montane Northern Hemisphere, with species in North America, Europe, and Asia, and a few reaching the southern continents. The plants grow on shaded rock, cliffs, walls, and moist woodland floors.Suggested Uses
Grown in shaded rock gardens, crevice plantings, walls, and woodland corners, where the lacy fronds soften stone and shaded ground. The small size suits troughs and containers in cool, shaded spots. Fragile ferns combine with mosses, small woodland bulbs, and other shade plants.How to Identify
Appearance
Size & Dimensions
Height4" - 1'6"
Width/Spread6" - 1'
Bloom Information
Ferns do not flower; they reproduce by spores rather than seed. Spores ripen on the frond undersides through summer, released from beneath the bladder-like covering. The fronds themselves are deciduous and die back by late summer or autumn.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Tolerates up to 4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Fragile ferns grow in part shade to full shade in cool, moist, humus-rich but sharply drained soil, often among rocks or in wall crevices. They suit shaded rock gardens, crevices, and the north side of walls where the roots stay cool and damp. Most species are hardy in USDA zones 3-8. Steady moisture during the growing season is needed, as the fronds wither early in dry spells, though the rhizome usually survives. The brittle fronds break easily, so a sheltered spot out of heavy traffic keeps them intact. Plants can be increased by dividing the rhizomes in spring.Pruning
Remove the dead fronds in late autumn or winter once they have died back. No other pruning is needed. Tattered or broken fronds can be trimmed away during the season to keep the plant tidy.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons