Growing Spiny or Spreading Wood Fern

This shade-loving species is a fern of many names. Variously known as the alpine buckler fern, spiny wood fern and the spreading wood fern, Dryopteris Expansa is a sturdy fern that is ideal for the wet and shady northern garden. In the wild, this fern grows in the Pacific Northwest of North America and in Central Europe.

Identifying Dryopteris Expansa

Dryopteris expansa is simple to identify and is one of the most common northern ferns. Spiny wood fern often grows in combination with the sword fern and the lady fern. The wood fern is smaller than its neighbor the lady fern (Athyrium filix-femina), with fronds that reach a length of 10 to 60 centimeters at a maximum.

Many people confuse spiny or spreading wood fern with bracken (Pteridium aquilinum), since the two have a similar triangular frond shape. However, while bracken pops up everywhere in meadows and in the garden, often in a single frond at a time, the wood fern or buckler fern has a rough, tough base that is covered in reddish-brown hairs that look like little spines.

Choosing a Location for the Spiny or Spreading Wood Fern

This fern is ideal for the wet and shady garden. Unlike the sword fern (Polistichum munitum), this fern is deciduous, which means that its fronds die back in the winter time and return in the spring. Be aware of this when planting it in the garden: it is not going to create winter cover for the riparian, wetland, or pond garden. However, the wood fern is lovely in the springtime as its fronds unfold. This fern is perfect for at the base of a small tree or a large shrub like a rhododendron, where it will provide beautiful foliage through the spring, summer and fall.

Planting Spiny or Spreading Wood Fern

To plant spiny wood fern, choose a place that is a little shady and amply moist, preferably with dappled sunlight. Give it room to spread its fronds up to 60 centimeters. This fern will also spread through its root rhizomes, so if there is an area of ground that needs to be covered, give this fern space and it may oblige. The spiny wood fern requires acidic soil and does well beside or on rotting logs.

Dryopteris expansa is a lovely and sturdy Pacific Northwest fern. It does well in open areas, where it will spread its fronds and spread through its rhizomes as well. It is a perfect complement to other Pacific Northwest native plants like the sword fern and the lady fern, but it will also hold its own in any wetland or pond-side garden.