Pacific Northwest Native Plant Profile: Deer Fern (Blechnum spicant)

Blechnum spicant

Since winter is well on it’s way, this seems like a good time to give a nod to a distinctive evergreen fern that brings elegance and function to moist, west coast coniferous forests, as well as shady gardens. Deer fern, known botanically as Blechnum spicant, comes from a large, extended family known as Blechnaceae (the chain fern family). The genus Blechnum actually has fewer members north of the equator than south (most of which live in the steamy tropics), and a few of the Ecuadorian cousins have managed to graduate to tree fern status, topping out at an impressive 10 feet tall! But our sweet little deer fern pays no mind to their staid accomplishments and remains forever a trim forest gem with many friends and admirers.

The Latin Blechnum comes from the Greek Blechnon, an ancient name for ferns, while spicant means “spikelike.” Its spikes are fertile fronds (which can be seen in the top photo) that rise vertically above the more earthly sterile fronds that produce no spores. Leaves on both types of fronds have oppositely arranged, shiny leaflets; the fertile ones are much narrower and have two rows of sori on their undersides. Deer fern looks attractive year round and its leaves often develop a coppery-red color in early spring.

Blechnum spicant

How it grows
This long-lived fern naturally occurs in southern Alaska, coastal British Columbia, Washington and Oregon (west of the Cascades), northern Idaho where it is classified as imperiled, and coastal California, as far south as Santa Cruz county, as well as the Sierra Nevada. It also occurs in parts of Europe. In western Oregon and Washington it grows from sea level up to montane zones and dominates the understory of what little remains of moist, old-growth forests, as well as second-growth forests.

Wildlife value
As you might expect, deer fern satisfies the winter hunger of deer, but also elk, caribou, moose, mountain goats, and bighorn sheep, especially in winter. It also provides year-round cover for small birds, mammals, insects, and other creatures. Birds may use the leaves as nesting material.

Try it at home
Deer ferns spread by thick, short, creeping rhizomes, and the key word here is short—as in stubby—which means they don’t spread nearly as fast as I would like. They prefer the misty air created by mature forest giants, the soft, moist, crumbly soil that comes from centuries of fallen detritus, and the symbiotic support of a real forest, not the drastically altered state of rectangular urban patches with hard, compacted soils and blistering heat. But don’t let that discourage you if you have close to the conditions deer ferns need: Shaded, relatively moist, somewhat rich soil beneath the protective canopy of (preferably native) conifers. A little dappled sun is fine if you can provide some supplemental water (especially when they’re young), but don’t try to grow them in bright, sunny places where sword ferns (Polystichum munitum) might do better. Allowing for a nice thick layer of compost or other organic matter (such as fallen leaves that break down by fungus and microscopic organisms) will help maintain moisture around their roots and add nutrients to the soil.

Although deer ferns are handsome close up as focal plants, they are at their loveliest when grown en masse as a ground cover. Since they grow to about two feet tall and wide, space them about two feet apart. Or, consider placing them a bit further apart and add the companionship of other native ground cover species that can nestle in between the ferns—this looks the most natural and will help keep down weeds and protect the soil.

Deer fern is a good sub for nonnative invasive plants such as English ivy (Hedera helix) and bittersweet nightshade (Solanum dulcamara).

deer fern & friends

In my backyard, deer fern mingles with maidenhair fern, piggy-back plant, and red-twig dogwood, all under the watchful eye of a youthful western redcedar.

Grab a partner
Deer fern does best with many other species that grow together within native plant communities. It thrives with native conifers, and in the Pacific Northwest they may include western redcedar (Thuja plicata), western hemlock (Tsuga heterophylla), Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis), noble fir (Abies procera), Sitka spruce (Picea sitchensis), and coastal redwood (Sequoia sempervirens), depending on the location. Deciduous trees like red alder (Alnus rubra) and vine maple (Acer circinatum) also make the cut. Understory species often found growing with deer fern include red huckleberry (Vaccinum parviflorum), thimbleberry (Rubus parviflorus), salal (Gaultheria shallon), devil’s club (Oplopanax horridus), queen-cup (Clintonia uniflora), false Solomon’s seal (Smilacina racemosa), Hooker’s fairy bells (Disporum hookeri), foamflower (Tiarella trifoliata), stream violet (Viola glabella), wild ginger (Asarum caudatum), piggy-back plant (Tolmiea menziesii), bunchberry (Cornus unalaschkensis), various mosses, and other ferns such as western sword fern (Polystichum munitum), ladyfern (Athyrium filix-femina), and oakfern (Gymnocarpium dryopteris).

© 2016 Eileen M. Stark

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