Monday, February 20, 2012

Actaea (Cimicifuga)

Actaea (Cimicifuga) – more shade garden plant selections

Names, names, names; some common names are bugbane, snakeroot, cohosh or fairy candles; in order to remove confusion the group was reclassified from Cimicifuga to Genus Actaea. However named these wonderful woodland plants can add background structure, height, and colorful foliage to your shade garden. There is a great deal of nominal confusion and many plants are sold with invalid names. The first specimen I added to my garden was tagged Cimicifuga racemosa ‘Atropurpurea’. This seedling strain from Korea and Japan has also been sold as C. ramosa or C. simplex ‘Atropurpurea group’. The species is now named Actaea simplex. It is difficult to tag what you are growing!
I always scan native plant nurseries and the internet looking to add a species or selections to my garden.
Many people are attracted to the pricey purple–foliaged selections from Actaea simplex, I have grown Hillside Black Beauty, Black Negligee, James Compton, and Brunette. The foliage will darken as the plant matures yearly. Native to woodland margins in semi-shade, shelter from high winds which can tear the plant apart.

A. simplex 'atropurpurea' emerging

Early to emerge, the plant will build a base of foliage from which grow flower spikes of bottlebrush white or pink flowers. Blooming in fall from late August in the case of A. americana to frost, some species are heavy scented attracting bumblebees.

North American native A. americana, American or Mountain Bugbane, has large compound leaves and stalked wands of  vertical white flowers. It grows 4-6 feet tall.  It differs from A. racemosa, Black Snakeroot or Cohosh with a single wand of snaking flowers. Blake Snakeroot is heavily collected for a compound used in drugs for menopause. Actaea rubifolia, is commonly called Appalachian Bugbane, has rounded maple-leaf like foliage.

Another Asian species I have collected is A. japonica, with glossy maple-leaf foliage. Often flowers are killed by frost, it has self-sowed infrequently. It averages from two to three feet tall.

Actaea japonica

Actaea rubifolia

Bugbanes- value in the garden

¨      Very cold hardy, USDA zones 3-7
¨      Prefer semi-shade woodland setting; rich, moist soils.
¨      Not invasive
¨      Infrequent care once established
¨      Fall blooming
¨      Unique colorful foliage
¨      Foliage and erect flower spikes add structure

My collector wish list includes three Asian species: A. dahurica with branched flower stems. A. mairei, a large plant with green flower heads eight feet tall. A. purpurea, is not in cultivation, it is reported to have purple-black flowers. There is also a variegated form of A. simplex which may not be cultivated in the United States.

I do love all their natural colors and forms but, the pollen dauber in me wants to create a purple-foliaged A. japonica or A. rubifolia. Different flower colors exist, A. foetida has yellow flowers, A. purpurea, purple flowers, I would love to experiment with different color combinations.
The most important task would be to propagate all species and hybrids and make them available to collector and gardener alike.

Hillside Black Beauty 1 yr. transplant

In the proper conditions bugbanes are highly sustainable shade plants which add attractive foliage, height, color, and fall flowering for temperate gardens.