Candy fern offers distinct features for garden enthusiasts and those interested in its historical applications. It presents an appealing option for specific landscape designs and has a rich background in traditional uses. Understanding its cultivation needs and varied applications helps integrate it effectively into diverse settings.
Unveiling the Candy Fern
Candy fern (Polypodium glycyrrhiza), also known as licorice fern, is named for its sweet rhizomes. Its gracefully arching, triangular, dark green fronds typically extend 10 to 12 inches, sometimes up to 30 inches. These once-divided fronds have pointed tips and finely scalloped or toothed margins, emerging from creeping rhizomes. The genus name, Polypodium, meaning “many-footed,” refers to its thick, reddish-brown, scaly rhizomes that spread along surfaces.
This taste comes from polypodoside A, a compound notably sweeter than sucrose. Native to the moist, temperate forests of the Pacific Northwest (Alaska to California, with disjunct populations in Idaho and Arizona), it thrives in shaded, damp locations. It typically grows at low elevations, often on mossy rocks, logs, or as an epiphyte on tree trunks, particularly bigleaf maples.
Cultivating Candy Fern
Successful cultivation of candy fern involves replicating its preferred natural conditions, focusing on light, soil, water, and environmental factors. This plant generally exhibits a low maintenance profile once established, making it a rewarding addition to suitable garden spaces.
Light
Candy fern thrives in partial to full shade conditions. While it can tolerate short periods of direct sunlight or bright filtered light, intense sun can scorch fronds. It suits areas with morning sun and afternoon shade, or under deciduous trees.
Soil
The ideal soil for candy fern is well-draining, humus-rich, and slightly acidic. It adapts to various soil textures (sandy, loamy, clay), but good drainage is necessary to prevent waterlogging and root rot. Placing the plant between shaded, half-buried rocks with leaf mold or organic amendments provides an optimal growing medium.
Water
Consistent moisture is important for candy fern, especially during its establishment phase. The soil should remain moist but not saturated, as overly soggy conditions are detrimental. Mature plants tolerate brief drought, but regular watering during dry spells maintains their semi-evergreen nature. In warm, dry summers, the fern may go dormant and die back, re-emerging with cooler, moister conditions.
Temperature and Humidity
Candy fern prefers cool, moist environments, typical of its native Pacific Northwest range. It flourishes in regions with warm, wet winters and cool, wet summers. Hardy to USDA zones 5-9, it requires adequate humidity, especially in drier climates, to support lush growth. It stays evergreen in cool, moist conditions, but may become summer deciduous if allowed to dry out.
Applications and Considerations
Candy fern offers diverse uses beyond its ornamental appeal, including traditional culinary and medicinal applications. Understanding its use and consumption precautions is important for anyone considering its integration into their garden or diet. Responsible harvesting practices also contribute to the long-term health of wild populations.
Traditionally, its sweet, licorice-flavored rhizomes were chewed for their pleasant taste. Indigenous groups in the Pacific Northwest also used these rhizomes to sweeten foods and unpalatable medicines. Beyond culinary uses, the rhizomes served as a traditional remedy for ailments like colds, coughs, and sore throats. As an ornamental, candy fern adds value to shade gardens, woodland settings, and rock gardens, forming attractive groundcover with its arching fronds. It also grows well in containers or as an epiphyte on logs and tree trunks, mimicking its natural habit.
When considering consumption, it is important to note that while generally considered safe, some ferns, including Polypodium glycyrrhiza, contain thiaminase, an enzyme that can deplete vitamin B. Thorough drying or cooking helps destroy this enzyme. Additionally, some ferns may contain carcinogens, so moderation in consumption is advised. Foraging for candy fern rhizomes should be done with care and selectivity, focusing on newer roots to ensure the plant’s continued health and reproduction. Buying from reputable nurseries is recommended to avoid impacting wild populations.