Dryopteris erythrosora - Copper Fern

Dryopteris erythrosora is one of the most hardy and ornamental evergreen ferns. Its feathery leaves change colour over time, creating a permanent and poetic setting in the shade of the undergrowth. Carried by reddish petioles, its fronds are almost pink when they first emerge before turning a lovely copper colour when mature. Plant it in the understory or in a partially shaded area of the garden, even in full shade. Easy to grow in humus-rich and moist soils, its cultivation is within reach of all gardeners.

Dryopteris erythrosora is part of a large group of plants called dryopteris ferns, which are all deciduous or semi-evergreen terrestrial species belonging to the Dryopteridaceae family. Native to eastern Asia, China, Korea, and Japan, this botanical species is found on wooded hillsides and embankments in cool and rainy temperate regions.

The plant grows from a short, creeping, and often branched rhizome. It forms an upright clump of large fronds measuring approximately 70cm (28in) in height and 40cm (16in) in width. Its croziers unfold in spring as young fronds that start off pale-pink, gradually turning coppery-orange and then finally becoming a vibrant and glossy green in winter. They are triangular, bipinnate, and composed of dentate pinnae, offering a beautiful architectural structure. The evergreen foliage regenerates in spring. It is advisable to cut back the old fronds damaged by the cold in late March or early April. This will make room for new fronds. Its species name, erythrosora, means "red sores": indeed, on the undersides of mature fronds, one can observe small red dots arranged in two parallel rows on either side of the rachis, which is the main vein. These are the sores, the "fruits" of ferns. When mature, the sores release spores that will be dispersed by the wind.

An authentic perennial for shade or partial shade, this robust dryopteris can tolerate temporary drought, which is common under the canopy of tall trees in summer, even in humid climates. It can be planted with helxine, eucomis, hostas, hydrangeas, shrubby fuchsias, and chocolate or caramel heucheras. It should always be planted in filtered light or shade. It will look incredible in a small exotic scene combined with Fatsia japonica, for example. You can also plant it in a large container filled with fertile soil. Place it in a slightly neglected corner of a patio, where its gorgeous fronds can emerge from the shadows.

The beautiful colouration of the fronds in spring and autumn has earned this fern its vernacular names of 'Copper Shield Fern', 'Coppery Fronded Dryopteris', or 'Autumn Fern'.