Rodgersia - Bold and Beautiful
(Editor's Note: This article was originally published on February 7, 2009. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
Rodgersia are relatively underused in the garden, yet for a bold impact, they are hard to beat. This genus was named in honour of US Admiral John Rogers (1812-82), commander of the North Pacific Exploring and Surveying Expedition on which Rogersia podophylla was discovered. There are 5 species within the genus, all native to east Asia, particularly Nepal, Korea, China and Japan. The genus is part of the Saxifrage family.
All of the species form large plants whose pinnate, deeply veined basal leaves arise from thick rhizomes. The leaves, which may reach 30 to 80 cm, emerge bronzy-green, become mat-green in summer and often turn brilliant yellow come autumn. They make admirable alternatives to Gunnera in colder climates or for smaller gardens. The flower stems may arise to 1.2 to 2 m, terminating in large sprays of numerous white, pink to reddish flowers in late spring or early summer. These heads are similar to a giant Astilbe flower. The star-like seed capsules often turn reddish in autumn.
In the wild, Rodgersia grow along streams, pond margins and seepage slopes. In the garden, they do prefer a moist, organic-rich, but not boggy, site in full sun to part shade. Regular watering will be required during dry weather. Avoid windy locations as their large leaves may get damaged. Propagation may be by seed or spring division. They are rated hardy to zone 5, possibly 4 with good winter protection.
The most popular species are R. pinnata and R. podophylla, but also available are R. aesculifolia, R. henricii and R. sambucifolia. In older literature, Astilboides tabularis was classified as a Rodgersia. Let's start with R. pinnata. This Chinese species has pseudo-pinnate leaves with 5 to 9 serrated leaflets. The flowers may be white, pink or red, depending on the cultivar. The most popular selection is ‘Superba', with rose-pink flowers and bronze-tinted spring leaves. ‘Fireworks' has cherry-red flowers and more distinctive bronzed spring foliage. ‘Maurice Mason' has bronzed spring foliage with reddish flowers. ‘Die Schone' is a German selection with dark pink flowers and very dark bronzed leaves. Perhaps the most spectacular is ‘Chocolate Wings' whose leaves are dark purple-bronze and retain the bronze tint all summer. Its flowers are also deep pink. ‘Alba' has white flowers and bright green leaves while ‘Elegans' is a pale pink version.
Details of R. pinnata
Rodgersia podophylla hails from Korea and Japan. Its leaves are palmate with 5 leaflets that are cleft and serrated mostly at their outer ends. Named selections include ‘Smaragd' a semi-dwarf with bright green leaves, ‘Pagode' which is extremely floriferous, ‘Rotlaub' with dark red spring leaves and ‘Braunlaub' whose spring leaves are dark bronze. All of these have creamy-white flowers. ‘Parasol' has bronze-tinted spring leaves and pink flowers.
On the left is a collection of R. podophylla cultivars including 'Pagode' (left side), 'Braunlaub' (far right) and 'Smaragd' (middle front). The middle picture is a closer view of 'Braunlaub' while the right picture is 'Rotlaub'
Rodgersia aesculifolia has pinnate leaves with 5 to 9 oval, serrated leaflets. As the name suggests, the leaves are very much like those of horse chestnut, Aesculus hippocastanum. Overall, this Chinese species is the largest-sized of all the Rodgersia. The flowers are white, tinted pink. The spring foliage is also bronze-tinted but in autumn, turn clear yellow. Meanwhile, R. henricii, from western China and Tibet, looks essentially the same but has dark reddish-pink flowers and more deeply bronzed foliage.
Details of R. aesculifolia (left and middle) and R. henricii (right)
The rarest in cultivation is the Chinese species P. sambucifolia. Its leaves are pinnate with up to 13 serrated leaflets. In this case, the leaves are reminiscent of elderberry, Sambucus nigra or S. canadensis. The flowers are white or pale pink and the spring leaves are typically bronzed.
Details of R. sambucifolia
Seeing as Astilboides tabularis was once considered a Rodgersia, I will include it here. This species has spectacular, shield-shaped, bright green leaves with serrated edges. The flowers are white and look similar to the standard Rodgersia. The leaves are up to 1 m across while the flower stems may reach 1.5 m. This plant lends a dramatic, tropical effect to the garden and comes very close to resembling a Gunnera.
Foliage details of Astilboides tabularis
If large bold foliage is your thing, then Rodgersia are for you! In a dappled shade garden, back of a moist border or next to a sunny water feature, few plants make as dramatic a statement as Rodgersia.
I would like to thank the following people for the use of their pictures: Equilibrium (R. aesculifolia), growin (R. sambucifolia and R. henricii), jamie68 (R. pinnata flower and foliage) and gmarr (R. pinnata leaf)