I’ve been very excited to see the increasing popularity and use of this very exciting perennial in our gardens and landscapes. New to me only seven short years ago, Crimson Fans red-leaved Mukdenia or hand fan (Mukdenia rossii ‘Karasuba’) is an exceptional addition to the palette for our partly shaded gardens. Formerly known as Aceriphyllum rossii, it is important to note that the commonly seen name of Crimson Fans is the translation of the original trade name of ‘Karasuba’ assigned in Japan. This selection has some specific characteristics, and for the purpose of this article, I’ll be using Crimson Fans Mukdenia for the sake of continuity.
The primary feature of interest from this member of the Saxifragaceae family is the increasingly intense reddening of the thickly textured foliage over the course of the summer (see photos). Transitional foliage coloration of herbaceous perennials is frequently under promoted and often overlooked in the garden. Crimson Fans Mukdenia, distant cousin to coral bells (Heuchera), is destined to create legions of fans with a solid contribution of ornamental features from spring emergence to hard frost. We’ll discuss the amazing foliage more in depth a bit later in the article.
Hardy from USDA Zones 4-9 (possibly to Zone 3), this compact perennial is native to rocky slopes and ravines of Eastern China and Korea. The naming of the genus commemorates the ancient city of Mukden, the Chinese capital city of the Manchu dynasty while the species honors British naval officer and Arctic explorer, Sir John Ross (1777-1856). Although adaptable to a wide range of soils, it is important to note that consistent moisture is vital for the successful establishment of Crimson Fans Mukdenia. This perennial is best grown in moist, fertile and well drained soils in partly shaded locations. Woodland settings with adequate moisture seem ideal and with this selection thriving in such situations, the term “woodland treasure” has been utilized frequently for this plant. Full sun is acceptable in more northern locations, provided that moisture is part of the equation. In hot and humid regions of its hardiness range, providing afternoon shade or dappled shade situations is vital for maintaining foliage integrity and vigor. As noted further below, the intensity of foliage coloration is related to the degree of sunlight available to the plant.
Spotlight on the foliage
Ornamental contributions start in early spring with bronze/green foliage emerging and unfurling in to palmate, rounded, 5-9 lobed, dentate leaves. The leaves look almost “maple-like” in their appearance and the increasing heat of late spring will transition the fan-shaped leaves to a glossy, dark green. Along with the emergence of foliage in the spring, small white, star-shaped flowers borne on dense, branched panicles appear on naked (leafless) 15- to 16-inch stems. The flowers are certainly ornamental, but only last about 10 days and will later form seed structures. Typically reaching a height of 9-18 inches and a width of 12-24 inches, this slowly spreading plant is great as a solitary accent piece but also has merits as a collective groundcover with multiple specimens planted roughly 24 inches apart. Notably, Crimson Fans Mukdenia has no serious insect or disease problems, although be alert for minor slug or snail issues at times. Deer and rabbits have not developed a taste for this perennial (yet?!). Propagation is achieved by seed (sown in fall for stratification) or through early spring division.
Back to the foliage, though. The transition from the bronze-green in early spring to the glossy dark green a month later is exciting but it’s the initial hints of reddish foliage color in early summer that catches the eye as the red tinting creeps inward from the leaf edges over the course of months. The coloration is variable from year to year, between specimens and even varies annually for individual specimens. The intensity of red, likely affected by many cultural conditions, is certainly impacted by available sunlight. Specimens in considerable shade will get some degree of red on the foliage but those that receive some amount of direct sunlight during the day or consistent dappled lighting will have the most exceptional transition to a significant red by early fall. Again, specimens in the cooler, northern part of their hardiness range can tolerate full sun if given adequate moisture. The best specimens I’ve ever observed did have some degree of afternoon shading.
As an “ingredient” in the partly shaded garden, Crimson Fans Mukdenia expands the compositional potential of any space due to the primary contribution of that transitional foliage. Combined with perennials with similar needs, both in moisture and sunlight, the texture and coloration of this selection goes well with a wide range of Hosta, Heuchera, Epimedium and most non-spreading ferns. My favorite pairings with Crimson Fans Mukdenia include ‘All Gold’ Hakone grass (Hakonechloa macra), maidenhair fern (Adiantum pedatum), and ‘Stairway to Heaven’ Jacob’s ladder (Polemonium reptans). Consider utilizing this selection along path edges and in groupings to augment and enliven the space. Do look for the variegated selection of Mukdenia rossii called ‘Starstream’ or the gold form found as ‘Ogon’. Terra Nova Nurseries Inc. has released an intergeneric cross of Mukdenia Crimson Fans and Bergenia which has resulted in x Mukgenia NOVA ‘Flame’ with the merits of both parents.
Mark Dwyer was the Director of Horticulture at Rotary Botanical Gardens in Janesville, Wisconsin, for 21 years. He has degrees in landscape architecture and urban forestry and now operates a private consulting practice, Landscape Prescriptions by MD. www.landscapeprescriptionsmd.com