Blechnum Ferns

The genus Blechnum, from the family Blechnaceae,  was derived from the Greek word blechnon meaning a fern.

Blechnum are mostly evergreen ferns with erect or creeping rhizomes and simply pinnate, leathery fronds, the fertile ones usually erect, the sterile often spreading. There are several species from around the world.

Blechnums make a decorative garden fern or container plant that adds interest and form to a shady area. It requires semi- to full-shade.  The plant does well in amongst other shade-loving plants and also makes a wonderful container specimen on a patio.

Blechnum tabulare

Mountain Blechnum; False Tree Fern; Valsboomvaring

The name is a direct reference to Table Mountain in Cape Town, the site where this fern was first collected between 1772 and 1774. This species can be confused with other species of Blechnum. Note the pinnae are unequally shaped, a character not displayed by the other species. This fern is also frequently mistaken for a small cycad. The growth habit of these plants at a distance looks similar, although they are not at all related.

The fern is widely distributed from the south-western Cape eastwards through South Africa to Zimbabwe, Mozambique, Malawi, Zambia, Angola, Tanzania, Kenya, Uganda, Zaire, Cameroon and Nigeria. It also occurs in Madagascar, the Mascarene Islands and Tristan da Cunha.

Natural habitat of the Blechnum

Blechnum tabulare is commonly found growing in grasslands along streams, often in rank vegetation, on grassy hillsides, along the margins of evergreen forests and quite often on roadsides.

Note that plants from the winter-rainfall regions have a large stem and could be classified as mini-tree ferns; also, the leaves are more lax, or arching. 

The plants from the summer-rainfall areas seldom have a stem higher than 200 mm and, if they do, it is horizontal; the leaves are held more erect, and the leaflets are commonly tapering. 

Blechnum brasiliense

Brazilian dwarf tree fern, Red Brazilian tree fern, red dwarf tree fern

This Blechnum is an evergreen, frost-tender fern reaching a height and spread of 1.5m by 1m. The erect to arching fronds are slightly crinkled; new fronds emerge an intense pinkish-red colour before maturing to a handsome, dark glossy green specimen. Over time, the erect rhizome will form a thin trunk around 30cm high.

Excellent for shaded, woodland type gardens or beside water features.

Blechnum gibbum

Silver Lady

An upright, usually single stemmed, fern, it grows 90cm tall and resembles a miniature tree fern. It makes a splendid specimen plant in a pot or in a shaded spot in the garden. This species does well in a sub-tropical environment.

What Blechnums need

Blechnums prefer regular water throughout their active growing season. They are fairly cold-hardy as ferns go, and do not relish any prolonged dry period. It is also important to provide high humidity, whether through a mister, humidifier or, for a potted fern, by setting the pot in a tray full of damp pebbles.

In a nutshell

  • Plant Blechnum ferns to add texture and form to any shade garden;
  • Choose a species that will thrive in your climate, depending on what is available in your local  garden centre;
  • Water well during the fern’s active growing season;
  • Keep ferns in containers on a tray of pebbles to increase humidity;
  • Feed your fern at the start of the growing season with a liquid fertiliser high in nitrogen to encourage lush foliage.
The Gardener