Gymnocarpium dryopteris

Gymnocarpium dryopteris is a very pretty little ground cover fern, better known as the oak fern or Polypode dryopteris. It is found in high-altitude undergrowth, where it often grows in cool and shady environments, in soil rich in humus and sand. It is delightful to see its lovely sprouts of spring green velvet fronds emerge from the ground at the end of winter, becoming more numerous each year. Its vigorous and wandering rhizome allows it to gradually colonise the soil without becoming uncontrollable. Perfect for bringing a little light under trees, this small botanical fern is easy to acclimatise in our gardens when the conditions are right. It is perfect in a naturalistic-inspired ensemble.

Gymnocarpium dryopteris is a deciduous fern belonging to the Woodsiaceae family. It is native to Europe, Asia, and northern America. It is a rather mountainous botanical species, preferring non-calcareous moist to wet soil. It is found in the Pyrenees, the Alps, the Ardennes, and Corsica, for example. Its natural habitat consists of shady and humid oak and wall undergrowth. It can also, but more rarely, be found in limestone soils covered with humus, which is therefore acidic. This perennial spreads with its creeping rhizome.

This very hardy fern grows in spring and remains dormant underground in winter. Its elongated and slender rhizome, equipped with fine roots, gives rise to strongly triangular fronds in March, ranging from 7 to 20cm (3 to 8in) in length. They are soft and smooth to the touch, carried by a slightly scaly long petiole, on average 30cm (12in) above the ground. The petiole is longer than the lamina, which is successively divided twice into crenate lobes. The colour of the leaves is a very tender green, which is bright in the shade. Capable of spreading on the ground for several metres, its growth rate is quite rapid. The plant produces sori (small sacs containing spores) arranged in two parallel lines along the median vein of the lobes, resembling small brown warts.

This little fern forms a delightful ground cover where it thrives. It brings a touch of lushness to shaded and humid areas of the garden, which are not always easy to landscape. Its magnificent tender green foliage is superb next to mossy stones. In filtered light or shade, it can be planted with lungworts, variegated ivy (Hedera helix 'Variegata'), helxine, and hostas. It can also be adopted in a Japanese-inspired garden, by combining it with hakone grass and a Japanese painted fern (Athyrium niponicum 'Pictum').