At present, Rocky Hills is a showplace for fiddleheads underfoot. But before 1990, attention was focused overhead. The garden began in 1956, when Henriette Granville Suhr, the head of furniture and interior design showrooms for Bloomingdale’s, and her husband, William, purchased the 13-acre farm as a weekend retreat. They had no serious background in gardening, but they discovered a passion for it as they transformed the property from a bramble-infested eyesore into a haven of outstanding shrubs and trees.
Planning a Shady Garden
By 1990, the garden had become a serene shady scene. Considering how to make use of the shade canopy, the then-widowed Henriette contacted fern expert John T. Mickel, Ph.D., senior curator emeritus at the New York Botanical Garden, and asked for advice on amassing a collection. A friendship was forged, and Mickel—who has 150 different ferns in his own yard and who authored Ferns for American Gardens (Timber Press; 2003)—ultimately shared 80 ferns from his personal garden collection. With his expertise as a scientist and Henriette’s talent as a designer (she spearheaded the concept of retail store showroom furniture displays), they pulled together a carefully documented carpet of ferns that creates the feeling of wading through the forest primeval. It turned out the garden’s dappled shade was ideal for ferns. Henriette avoided planting beneath groves of conifers, which furnish too dense of a canopy. Trees with surface-root competition, such as Norway maples, can also jeopardize thirsty ferns. Despite the predominating rocks that gave Rocky Hills its name, Henriette found soil pockets between the stone formations to plant. She watered frequently, especially when the fernery was being established. Other than needing water and pine-bark mulch to prosper, the plantings quickly slipped into autopilot to form a luxuriant, magical Oz.
Long-Lasting Foliage
The result is a harmony of crosiers in the full spectrum of green with touches of frosty silver and burnished bronze from relatively colorful painted ferns (Athyrium niponicum var. pictum). The frond carpet lets the azaleas and rhododendrons shine, while low-growing ferns form a flowing weave below spring flowers such as Spanish bluebells (Hyacinthoides hispanica), primroses, forget-me-nots, and spring bulbs. And spring is only the beginning, because most ferns persist in prime plumage through autumn, providing a soothing green seafoam interlaced among hostas, Jack-in-the-pulpits, Solomon’s seal, and hardy begonias. They might not be “look at me” plants, but ferns go the distance with subtle style. Although Henriette passed away in 2015, Rocky Hills and its collection of ferns flourish under new stewardship. The current owners continue the Suhrs’ dedication and open the garden to the public through The Garden Conservancy Open Days Program. Visit gardenconservancy.org for more details about this year’s Rocky Hills Open Day on May 19, 2018, and become immersed in verdant paths with fiddleheads swishing at your feet.
Fern Plant Combinations
Beneath the lacy shade of a dawn redwood (Metasequoia glyptostroboides), a tapestry of sensitive fern (Onoclea sensibilis) and ostrich fern (Matteuccia struthiopteris) weaves together with forget-me-nots (Myosotis scorpoiodes). With green as a base color, the purple and yellow flowers pop. A simple wood bench sits at the edge under the redwood, providing the perfect place to enjoy the natural beauty.
Planting for Your Zone
The fascinating fronds of the crested hart’s tongue fern (Phyllitis scolopendrium ‘Crispa’) look otherworldly, but actually are perfectly hardy from Zones 5–9. Unlike most of its fellow ferns, the hart’s tongue prefers some lime in the soil. Seemingly delicate but surprisingly stoic, the northern maidenhair (Adiantum pedatum) spreads to form a handsome colony of chartreuse fronds. It is hardy in USDA Zones 2–8.
Fern Colors
In May and June the Rocky Hills gardens are filled with spring-blooming bulbs, shrubs, perennials, and flowering trees, as well as banks of graceful ferns. While green is often associated with spring, not all ferns show green foliage early in the year. The young foliage of autumn fern unfurls striking orange and bronze fronds before turning green in summer.
Groundcover Plants to Control Weeds
Forming a dense groundcover to muscle out weeds, a crazy quilt of Himalayan maidenhair (Adiantum venustum), painted fern (Athyrium niponicum var. pictum) and Christmas fern (Polystichum acrostichoides) hugs the ground between the eponymous boulders of Rocky Hills. The mix of lime, silver, and emerald foliage creates depth and emphasizes the unique texture of each fern variety.
Gardening in Rocky Soil
Ferns find a way to tuck themselves into all kinds of nooks and crannies. Although the rocky base of this stone wall might not be optimal, ostrich fern (Matteuccia struthiopteris) and painted fern (Athyrium niponicum var. pictum) nevertheless find a way to thrive. These varieties cover the color bases: classic green and something with a little more pizzazz, like variegated cream, mint, and plum.
Shade Trees
Many mature trees at Rocky Hills—and there are dozens of species—create the dappled shade that ferns enjoy. The spotty shade keeps ferns (and other shady plants) cool and wet, and keeps the hot sun from singeing delicate foliage and flowers.
