As the first fiddleheads of spring start to unfurl, ferns are again finding their place in the modern garden.
The beautiful evergreen foliage and vase-like form of Dyce’s holly fern (Polystichum × dycei) make a great specimen for the woodland garden. Photo by Richie Steffen, Elisabeth C. Miller Botanical Garden
The notion that all ferns look alike has been completely upended by a resurgence of exciting new ferns and a broad array of proven performers.
Hardy ferns have been steadily gaining popularity and feature prominently in trends favoring a focus on texture, long-lasting landscape interest, shade gardening and container gardening. Over the last decade, a multitude of exciting species and beautiful cultivars has hit the market, making now a great time to explore this time-tested group of plants and see what they have to offer the modern garden.
This is not the first time the public has held ferns in high regard. In the mid-1800s, the Victorians discovered the virtues of these exceptional plants and selected hundreds of cultivars, some of which are common in our gardens today. Avid growers in Japan have also contributed greatly to our current selection of ferns.
Many of the new ferns available are prodigy that can link their existence back to dedicated Japanese and British growers and gardeners.
Tried and true
Some of the best ferns for the garden are natives from the Pacific Northwest. Western sword fern (Polystichum munitum), deer fern (Blechnum spicant) and Western maidenhair fern (Adiantum aleuticum) are all beautiful, easy to grow and a great place for gardeners to start. But there is much more out there, and many are trouble-free and resilient in the landscape.
Fortunately, it is easy for anyone to find the full range of tried-and-true ferns. Great Plant Picks (www.greatplantpicks.org) is a Northwest-based non-profit plant education program run by the Elisabeth C. Miller Botanical Garden. GPP has selected 32 ferns that have shown exceptional performance in our climate. A visit to the website will provide clearly written information about these great ferns.
The autumn fern (Dryopteris erythrosora) is the most popularly grown fern and for good reason. It is fully evergreen, very hardy in USDA zones 6–9, and tolerates deep shade to half-day sun. The fronds emerge in the late spring with bronzy red-orange new growth that is slightly more intense on the cultivar ‘Brilliance’. A medium-sized fern, it can reach heights as tall as 30 inches, but will typically grow to 18–24 inches tall and stays as a loose clump. It is versatile and does not disappoint.
The Victorian cultivars that survived over the last hundred-plus years were enduring plants that tolerated neglect. The dwarf crisped golden-scaled male fern (Dryopteris affinis ‘Crispa Gracilis’) and the divided leaf soft shield fern (Polystichum setiferum Divisilobum Group) are great examples.
The dwarf crisped golden-scaled male fern is one of the best small ferns available. Rarely growing more than 8–12 inches tall, the deep, dark green fronds form a tight upright vase shape. It is evergreen but benefits from being cut back in March prior to the new fronds emerging. Try using it in containers or shady rock gardens.
The divided leaf soft shield fern, commonly referred to as “Alaska fern” in the Northwest, is exceptionally easy to grow and has the added bonus of tolerating dry shade. Gracefully forming a wide, low mound, this fern will mature to about 15–18 inches tall and 24–39 inches wide. The soft, feathery fronds look delicate, but they are fully evergreen and do not break easily.
Although Alaska fern can be cut back in March, the old fronds look good well into early summer, and often the new fronds will cover the old fading fronds adequately. It is pretty enough to be used as a specimen but also looks great when mass planted.
A favorite for creating a bold statement is the purple-stemmed royal fern (Osmunda regalis ‘Purpurascens’). This deciduous fern can grow as tall as 6–7 feet in rich, moist soils and bright light, but a more typical size is 4–5 feet tall and nearly as wide. In spring, the fiddleheads emerge reddish-purple and hold the color well into summer.
The adaptability of this plant is remarkable, tolerating soil conditions from wet to dry (for short periods) and clay to sand. It is one of the few ferns with surprisingly good fall color, turning a glowing golden yellow.
The go-to fern for colorful foliage has always been the Japanese painted fern (Athyrium niponicum var. pictum). This is a great fern for shade, as it will quickly burn even in partial sun. There are several hybrids between the beautiful painted fern and the tough lady fern (Athyrium filix-femina). Hybrids such as ‘Ghost’, ‘Branford Beauty’ and the recently released, giant-sized ‘Godzilla’ are proving to be great garden plants that grow best with at least some sun, while providing a great, long-lasting color spot in the landscape.
New and exciting
The choice of ferns available is at a high, and the renewed interest has led to several exciting new introductions. Three of the most spectacular additions to our plant palette are Dyce’s holly fern (Polystichum × dycei, pictured above), Bevis soft shield fern (Polystichum setiferum ‘Pulcherrimum Bevis’) and the single jeweled chain fern (Woodwardia unigemmata). All make exceptional specimens for the garden show with their bold texture, foliage and form.
Dyce’s holly fern grows rapidly to 24–30 inches tall and a little over 3 feet wide, forming a gracefully arching, wide vase shape. The shiny, dark evergreen fronds hold up well through the winter. Mature plants produce small bulblets on the tips that can be easily rooted. This is a very easy and vigorous fern to grow, and should become a staple in the industry.
One of the best cultivars from the Victorian era is Bevis soft shield fern (P. setiferum ‘Bevis’). Selected for its delicate and graceful growth, it is often remarked to be one of the most beautiful of the Victorian selections. Reaching about 3 feet tall and 3 feet wide, it will develop an evenly layered form that is the essence of perfection. This sterile cultivar was quite rare and expensive until it was recently produced through micropropagation. Give this fern time to mature: the true elegance will not develop until it is 3–4 years old.
One of the most spectacular and bold ferns that I have grown is single jeweled chain fern. This Asian native has huge, low-spreading fronds that typically reach 4–5 feet in length. If provided with rich moist soil and a sheltered position, fronds can tip the scales at 8 feet long! If that was not enough, the new fronds emerge a deep burgundy red, then brighten to blood red before gradually maturing to a rich green. This fern can be damaged in a cold winter, so be sure to protect the crowns during early frosts and extended freezing weather.
Of the newly available species, these four look to have a lot to offer gardeners, growers and retailers: Mairis’s maidenhair fern (Adiantum × mairisii), shiny bristle fern (Arachniodes davalliaeformis), Koidzuma’s wood fern (Dryopteris koidzumiana) and silver saber fern (Polystichum xiphophyllum).
Maidenhair ferns have no equal for garden appeal, and hardy forms are few and far between. Mairis’s maidenhair fern is especially wonderful because it will grow best in bright, open shade with up to half a day of sun — without burning the bright green, delicate-appearing foliage. This robust grower reaches a modest 15 inches tall and forms a lacy clump over time. Hardy to USDA Zone 7, it will weather through most winters with no problem.
The forest green leaves of the shiny bristle fern will immediately catch your eye. This smaller fern grows to about 12 inches tall and is clump forming. The leaves are very shiny with a uniquely prickly appearance, yet are soft to the touch. The foliage is evergreen and holds up well through the winter, but the new growth is late to emerge in the spring — so be patient! Hardy to USDA Zone 7 and best in bright to open shade, it is well worth trying.
If you like red, no other fern can compare with Koidzuma’s wood fern. In late spring to early summer, glowing orange-red new fronds emerge. Hardy to USDA Zone 7, this unique fern loves heat, so patience is required for it to start growing. But once it does, new fronds emerge with their brilliant color through summer into early fall. Plant in a location with bright, open shade to a half-day of morning sun and rich soil with regular watering during dry weather.
More subtle yet very enthralling is the silver saber fern. A smaller fern for the garden, it reaches about a foot tall and 15 inches wide. The dark green fronds have a distinctive silvery overlay that is particularly pronounced in shade. The leaves are firm and tough, and hold up well through the winter. This fern will tolerate dappled to dark shade if given rich soil and regular watering during dry weather. It is quite hardy, down to USDA Zone 6. This small, slow grower is a charming addition to any shade garden.
This brief look at ferns only covers a handful of what now can be found in the market. The beauty, versatility and garden performance are well worth taking a new look at these remarkable plants.