Ferns are a study in contrasts. Lacking showy flowers, their simple leafy appearance belies their incredibly complex, yet highly successful, reproductive strategies. The relatively few number of ferns used in the horticulture trade contrasts sharply with the thousands of ferns and "fern allies" found worldwide in a vast array of habitats. Fortunately, the ferns we use most often indoors and out are all beautiful, versatile, and abundant in the Lowcountry.
Ferns typically thrive in our humid, tropical, summer weather. Most of them prefer moist organic soils and shade to part-shade conditions to thrive in the garden, yet many are more drought-tolerant than we think.
I compare ferns in the landscape to a cool drink of water on a hot day. Their verdant leafy fronds are refreshing and forgiving whether they are hanging on a gracious Lowcountry porch, covering the ground in a shady woodland garden, or providing classic lines to containers or window boxes.
Some of my favorite ferns are hardy evergreen or deciduous perennials that create cool niches in shady gardens.
Ferns fill visual gaps with their arching fronds and pleasing textures that vary from fine and feathery to coarse and leathery.
Autumn Fern (Dryopteris erythrosora) is one of my favorites. It is a drought-tolerant, non-native perennial fern that reaches 2 to 3 feet tall. The common name derives from the coppery pink of the new fronds as they unfurl each spring, mature to bright chartreuse in summer, and persist during mild winters. Their evergreen quality makes them a good choice for deciduous woodland gardens. This winter was tough on my autumn ferns, but with a little trimming of the cold-damaged fronds, the new fiddleheads have emerged and are as pretty as ever.
Where would Lowcountry gardeners be without hardy, deer-resistant holly fern (Cyrtomium spp.)? Holly ferns may seem boringly overused but their shiny, coarse-textured fronds and low maintenance requirements make them a good solution to many landscape problems. Given adequate moisture, holly fern will tolerate nearly full sun.
Native cinnamon fern (Osmunda cinnamomea) provides drama in the garden. While most ferns demurely hide their spores on the underside of leaflets, cinnamon ferns boldly unfurl their fertile fronds in showy spring displays. The cinnamon-hued reproductive structures provide vertical focal points in the garden that are surrounded by lush fronds spanning as much as 6 feet. Plant cinnamon fern in light to heavy shade in rich organic soils with adequate drainage. Don't fret about placing them in the perfect location as they are quite versatile, thriving naturally in a range of conditions from the edges of shady, boggy places to dry, sunny patches on the forest floor. Cold weather forces these lovely ferns into dormancy, which only makes their appearance in spring all the more dramatic.
Two native Florida ferns are commonly found swinging in baskets on American front porches and gracing containers and window boxes. Boston ferns or sword ferns (Nephrolepis exaltata 'Bostoniensis') prefer bright, indirect light and high humidity. Cultivars such as 'Dallas' offer ruffled fronds and require less humidity, resulting in far less shedding when overwintering these ferns indoors. Like most ferns grown in containers, these classics prefer humidity and moist soil but will not survive long when overwatered.
Giant sword fern (Nephrolepis biserrata), often sold under the name 'Macho Fern,' is a reliable perennial in middle Florida and farther south. Their sub-tropical origin means they may not survive in zone 8b when temperatures drop for long periods. Use them as annuals, or overwinter indoors by cutting fronds back to a manageable size. Maintain even soil moisture and provide bright indirect light over the winter and repot in the spring if needed. During the growing season, these beefy ferns, with their huge arching fronds, enjoy bright morning sun and filtered afternoon light.
While ferns are classified within the plant kingdom, these primitive plants reproduce via spores, not seeds associated with more "modern" flowering plants. Scientists typically group similar spore-dispersing plants into a category known as "fern allies." Club or spike moss and horsetails are two of these ancient plants. Planted with ferns, Selaginella kraussiana 'Aurea' or golden spike moss creates an instant woodsy, natural feel for containers and window boxes. Pair these with ferns that also prefer low light and consistent moisture for simple, cool container combinations.
Join Clemson Extension's Carolina Yards for a five-week, online course designed to help Carolina gardeners learn to grow and maintain an environmentally friendly garden. Enjoy online training from the comfort of your home and on your own schedule with peers from around the state. Each week includes online presentations, videos, discussion forums and more.
Visit www.clemson.edu/cy/online for more information and to register. Register by April 24 to take advantage of the early registration fee of $110. The fee includes online training and a package of course materials shipped to your home. Space is limited.
Are you one of the more than 6,000 owners of a stormwater pond in the tri-county area? The 2014 Charleston Area Stormwater Pond Management Conference on May 22 will provide a forum to share the latest pond management information and resources for the Lowcountry community. Conference agenda features discussions and lectures from pond management experts as well as an exhibitor demonstration area.
The one-day conference will be held at Trident Technical College; registration starts at $50.
To sign up, visit www. ashleycooper.org.
Amy L. Dabbs is a Clemson Extension Urban Horticulture Extension Agent. Send questions to firstname.lastname@example.org.