If you believe, as I do, that the most deeply satisfying gardens are ones not of flowers alone but of form and line, of texture and shades of green, then have I got a plant for you.
The fern is primal not only in its botanical lineage but also in the way it stirs a deep connection to something primordial; it wells deep within us.
And yet it is not primitive. Far from it. Fern plantings imbue a garden with sophistication — if only more people knew it.
A plant that may have climbed out of the bog remains one of the last underused and undervalued treasures of the garden, a perennial that does not flower but adds a simple beauty to almost any space that is in light to full shade.
The problem for the fern is that it was always viewed as a default plant, one to stick in a deep corner of the garden that’s too gloomy for anything else. There have long been handsome fern species, but in the past few years, growers have introduced spectacularly beautiful ferns with more colors than green. At the same time, interest in native plants has heightened awareness of indigenous ferns.
What ferns lack in bloom power, they make up for in other ways. In addition to their refinement, they are little bothered by pests and diseases, so you don’t need to spray them with nasty chemicals.
Moreover, ferns are not troubled by deer, rabbits, squirrels, groundhogs, chipmunks, voles and the rest — these pesky mammals are a real bane to those of us who grow other plants, but when it comes to ferns, these creatures are largely uninterested. (A deer may find a fern glade a nice place to make a bed.)
“Twenty-five years ago, you might have found nine ferns to plant. Today, we produce about 160 different varieties, maybe 100 for landscape use,” said Kent Kratz, vice president for research for a major wholesale fern grower, Casa Flora, based in Dallas.
The only real consideration when planting a fern is that the soil has some organic matter and is not allowed to dry out. Ferns will take more sunlight than you imagine and less shade. If you have darkness the whole day long, stick in an aspidistra.
Because ferns have different visual punch and range in size and soil needs, you need to place them with thought. The good news is that the Mid-Atlantic region is a fern nirvana in that we can grow ferns from more northern and southern regions — for example, the cold-loving ostrich fern or the Southern maidenhair.
With such a large palette available, ferns can be used as accent plants, as specimens, as ground covers and as filler plants. When you place different species together, something amazing happens: You see that they are not all the same.
I traveled to one of my favorite haunts, Chanticleer Garden in Wayne, Pa., to see how my horticultural friends use ferns imaginatively and to great garden effect.
Under an oak grove formerly carpeted with lawn, the gardeners have converted the area to ground-cover plantings of the autumn fern variety Brilliance in a combination with the Dixie wood fern. An area of utilitarian grass has become an absorbing garden space and, by the way, a better place for the trees because turf and hardwoods have different watering and fertilizing needs.
In the Bell’s Woodland garden at Chanticleer, Przemek Walczak showed me a highly effective massing of the Christmas fern (Polystichum acrostichoides). Named for its evergreen fronds once used as holiday decorations, the Christmas fern is a stalwart of the shade garden because of its architectural quality — a medium-size fern that is upright and arching — and the way its dark green fronds capture and reflect the light.
Here, he has planted a generous ribbon of Christmas ferns amid a patch of foam flower, which was a froth of bloom in spring but is still attractive in leaf, and the grasslike oak sedge (Carex pensylvanica).
The Christmas fern is one of the easiest ferns to grow and takes a range of conditions. In winter, the old fronds flatten to the ground to await the emergence of new growth in the spring, when ferns produce their distinctive coiled fiddleheads. “I don’t even cut it back; the new fronds come through the old foliage,” Walczak said.
In larger shade gardens, ferns can be planted as an alternative to the blankets of mulch that are spread each year to provide a visual uniformity and to keep weeds at bay. Two related ferns will colonize nicely in such places — the hay-scented fern and the New York fern. They may be too eager to please in a small urban garden, but given some room they will light up a glade with their bright yellow-green foliage. The hay-scented fern is particularly fine-textured, almost feathery, and smells of fresh mown hay when bruised. It grows to 24 inches and you determine the spread. The botanic name is Dennstaedtia punctilobula.
Carl Taylor, a noted botanist and fern expert who gardens in Arlington, reminded me that the hay-scented fern will take much more sunlight than most other garden species, though, like most ferns, it will get ragged if neglected through a drought.
The New York fern (Thelypteris noveboracensis) is similar in its size and its desire to spread, but it has its place in the right setting. I like the paradox of these two extremely delicate-looking plants having such vigor. Walczak said that if they look tired and frazzled in the midst of a dry summer, you can cut them back, and with some watering they will grow back spring-fresh.
I asked Taylor what he might grow in an area of dryish shade, and he commended the marginal wood fern (Dryopteris marginalis), which is a medium-size evergreen fern with a blue cast to its leaves. Another choice, he said, is the related Goldie’s wood fern (Dryopteris goldiana), which is larger and has distinctive brown fiddleheads in the spring.
Dryness hasn’t been a problem this summer; it has been a banner year for ferns. They look as fresh as they did in May, but about twice the size.
Walczak took me to see a clearing where he had planted a mass of New York ferns behind a single glade fern and a few Northern maidenhair ferns. The leaflet, or pinna, of the glade fern is quite coarse and contrasts strikingly with its wispier neighbor. The botanic name is Diplazium pycnocarpon. “This is one of my favorites. The appearance is similar to Christmas fern but lighter in color and more robust,” he said. “It mixes well with other ferns.”
The glade fern likes its location on the moister side, and if you have damp areas, there are several other sterling ferns that will grow where such woodland perennials as heucheras and hellebores will peter out.
The ostrich fern (Matteuccia struthiopteris) is a monster, and it spreads by wiry black runners. In optimum locations, its fronds can grow to six feet or more, but it has its place in a large property afflicted with wet soil. In such a garden, you could position ostrich ferns in and around other bog lovers: winterberry, Yaupon holly or river birch, or the herbaceous hardy hibiscuses, swamp lobelias or ligularias.
Another wet-loving fern is the swamp fern (Dryopteris cristata), which is small to medium in stature but handsome in its upright and archetypal form.
Three species of native fern — all related — love damper conditions and will be found in any fern connoisseur’s garden. (They’re also among the easiest to find in nurseries and garden centers.) The royal fern (Osmunda regalis var. spectabilis) grows from three to five feet, and a plant can attain the presence of a shrub if planted in rich soil at a key spot along a path in dappled shade.
The cinnamon fern (Osmunda cinnamomea) is named for the way its fertile, spore-bearing fronds form attractive cinnamon-brown wands amid the green foliage. The third osmunda is the interrupted fern (Osmunda claytonia), named for the way its small, dark, fertile leaflets appear in the midst of the green fronds. It grows to four feet and, like its cousins, is distinctly upright and eye-catching.
Walczak’s colleague Lisa Roper gardens in a sunnier part of the property and wanted to show me how the Japanese painted fern will spread, gently, as seedlings that appear spontaneously in the crevices of Chanticleer’s Ruin garden. I’ve noticed the same phenomenon in my garden, where they have appeared in the dirt between a brick path. Like most ferns, they take about three years after planting to attain their full size.
Roper pointed out a less flashy fern — a variety of the Polypodium vulgare named Uulong Island — that has established itself nicely. It creeps along the ground and spreads when happy, but never overpowers its space. It is evergreen and slow to present its new season’s growth but is surprisingly tolerant of hot, dry sites. “I water it in summer a couple of times a week,” she said.
Before I left, she wanted to show me another fern that needs greater use. It was a species of wood fern called Dryopteris crassirhizoma. It has robust, tropical-looking fronds, and its arching structure would make it the perfect pathside specimen. Hers had grown to about 30 inches tall and wide after four years, although it would grow bigger in an enriched bed.
Viewing this, I was reminded of Kent Kratz’s earlier comment: “I don’t think the appreciation for ferns has peaked yet.”
A handful of common ferns, such as Japanese painted and holly ferns, are typically stocked at mass merchandisers. The popular Boston fern, in spite of its name, is a tender plant that can be used as a summer-into-fall annual. It is effective in shady beds and outdoor containers.
Independent garden centers now have a robust selection of more unusual hardy ferns. Check ahead for availability.
Below are among the mail-order nurseries with a range of species and colorful variants. Some wait until September to ship.
Chat Thursday at noon Join Higgins for a live Q&A about gardening.
Read more: Higgins’s five favorite ferns
More from Home & Garden: