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By Amy Grant
You've probably heard about black cohosh with respect to women's health. This interesting herb plant has much to offer the garden too. Read here for more information on black cohosh plant care.
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|Family:||Ranunculaceae (ra-nun-kew-LAY-see-ee) (Info)|
|Genus:||Actaea (ak-TEE-uh) (Info)|
|Species:||simplex (SIM-plecks) (Info)|
|Cultivar:||Hillside Black Beauty|
|Additional cultivar information:||(PP9988, Atropurpurea Group aka Purpurea)|
|Registered or introduced:||1995|
Average Water Needs Water regularly do not overwater
USDA Zone 3a: to -39.9 °C (-40 °F)
USDA Zone 3b: to -37.2 °C (-35 °F)
USDA Zone 4a: to -34.4 °C (-30 °F)
USDA Zone 4b: to -31.6 °C (-25 °F)
USDA Zone 5a: to -28.8 °C (-20 °F)
USDA Zone 5b: to -26.1 °C (-15 °F)
USDA Zone 6a: to -23.3 °C (-10 °F)
USDA Zone 6b: to -20.5 °C (-5 °F)
USDA Zone 7a: to -17.7 °C (0 °F)
USDA Zone 7b: to -14.9 °C (5 °F)
USDA Zone 8a: to -12.2 °C (10 °F)
USDA Zone 8b: to -9.4 °C (15 °F)
Flowers are good for cutting
This plant is attractive to bees, butterflies and/or birds
N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed
This plant is said to grow outdoors in the following regions:
On Sep 8, 2019, RosieDay from Greenfield, NH wrote:
Lovely foliage but mine isn't more than a foot tall after a few years. Might be in too much shade there has also been some suspected deer nibbling despite alleged deer resistance. I'm going to move it to where it gets some sun and will spray deer repellent regularly.
On Dec 2, 2012, ShelbySnider240 from Roanoke, VA (Zone 7a) wrote:
I grow the "Black Cohosh" in my shade garden in Roanoke, VA. It does very well and has beautiful blooms. A friend gave me mine and she said it grew wild in the woods near her.
On Jul 5, 2012, yumabase from Youngstown, NY wrote:
I planted 6 black cohosh roots / bulbs this spring. Only 3 came up, and since May they have only grown to about 10 inches. The soil is good and there in mostly shade and moist. The P.H. Is just above 5.5, and I use a liquid fertilizer every two weeks.
I understand that there supposed to grow as much as 2 feet a month. Everything els growing in this garden is doing great.
What am I doing wrong?
On Jun 16, 2012, 730chicagogirl from Arlington Heights, IL wrote:
I LOVE this plant but I have had trouble with it. The first year, it was okay until Sept-Oct. Went out and the plant was totally gone. couldn't see a single stem. My neighbor actually suggested that someone took it. I just chalked it up. But the next spring, there it was, growing and looking good. Did well. This year, it started out strong, . and again, overnight, parts of it are drooping, stems seem bent and broken, and leaves are dry and/or soggy. Had to cut away 50 percent of plant and am hoping it makes it. Help!
Tell me it's not chipmonks.
On Dec 1, 2006, bluespiral from (Zone 7a) wrote:
In the Baltimore, Maryland area, this plant produces a lot of viable seed which has self-sowed in our garden. The offspring's leaves are not as dark purple as the parent, but, still, the leaves do have an interesting "smoky" tinge to the leaves. With its unique, sweet fragrance that carries far into the garden, this is a plant well worth winter sowing.
On Apr 8, 2005, nevadagdn from Sparks, NV (Zone 7a) wrote:
This plant survived the winter, but it was a little slow to appear (well, slow by my impatient standards) this spring. It's up now. It was truly beautiful when I planted it last fall.
On Dec 11, 2004, Todd_Boland from St. John's, NL (Zone 5b) wrote:
This new selection is even blacker than 'Brunette'. Otherwise, everything else about the plant is the same as for C. ramosa. More sun will keep the foliage darker. More moisture will make the plant reach 6 feet plus.
On Dec 3, 2004, levilyla from Baltimore, MD (Zone 7a) wrote:
The foliage is absolutely beautiful .. no afternoon sun on it however. the flowers in September are intoxicatingly fragrant.
When we garden under the woodland canopy, we take inspiration from how a forest naturally grows. To this end, I encourage you to spend plenty of time at your site before you do any planning. Walk the woods—even a tiny patch—to get a feel for the energetics of the forest and to look for notable features that will give insight into what you’ll be able to grow.
The key to a successful woodland garden is to select medicinal and edible plants that are well suited to the geography and ecology of your site.
As you explore, you’ll want to take special note of existing tree and understory species, slope and orientation (what direction your site faces), and soil quality. All of these details will help you map out future plant communities for the garden.
Possibly the most helpful thing you can do is to consider the native flora—most woodland medicinals grow in the companionship of certain tree and understory species. This means that the plants already present in a forest will give you valuable information about what else might be able to grow there. If you notice, for example, that ginseng and wild ginger (Asarum canadense) are thriving, you can infer that other medicinals who prefer similar growing conditions might do well there.
Use the lists in the section on Choosing Woodland Herbs for Your Garden below to learn which plants and trees grow well together and enjoy the same habitats.
If you’re working with a young forest, or one that has been damaged, it’s possible you won’t find many (or any) existing medicinal species. This doesn’t mean you can’t grow woodland herbs! But do take extra note of the existing tree species, as well as the other considerations described below when choosing plants for your forest garden.
You’ll want to pay attention to the slope and orientation of your site. If you live in a mountainous or hilly area, take special notice of the direction that any slopes face. For instance, north-facing slopes or gullies tend to be the moistest, shadiest places in a mountain forest herbs such as ginseng and trillium (Trillium spp.) might thrive there. South-facing ridges are the driest and sunniest herbs such as lowbush blueberry (Vaccinium spp.) are better suited to that habitat.
Keep in mind that the presence of creeks and springs can create cool, moist microclimates even on southern slopes, so try not to rely on orientation alone.
Finally, assess your soil. Get your hands in the dirt! If you already have a rich soil ecology to work with—think black, duffy goodness—you may be able to plant seeds and starts directly. However, if you want to up your garden game, you can collect a soil sample and send it to your local extension office for analysis. This will give you information about nutrient concentration and soil pH (a pretty important factor for growing forest medicinals). See the section on Choosing Woodland Herbs for Your Forest Garden below for more information on how pH affects woodland plants.
Also take note of soils that may be overly clayey or sandy. If this seems to be the case, adding organic matter will vastly improve your forest garden potential. Good options for organic matter include pine bark fines, compost, and homemade leaf mold.
Little sweet Betsy toadshade (Trillium cuneatum)
Black cohosh (Actaea racemosa) was used by Native Americans as an herbal remedy and its popularity continues to this day. This plant is native to eastern North America and is found throughout Virginia except for the outer coastal plain. It grows in a variety of woodland habitats, and is often found in small woodland openings. If you are not interested in growing this native for its medicinal properties (and PMG is not endorsing its use), is it still an excellent addition for your shade garden? If you are looking for a plant with dramatic flair, the answer is a resounding “Yes!” Before we consider its ornamental value, let’s quickly address its use in herbal medicine.
Black cohosh is a member of the buttercup family (Ranunculaceae). Other names for this rhizomatous forest herb include snakeroot, black bugbane, rattleweed, macrotys, and rheumatism weed. It is reputed to have analgesic, sedative, and anti-inflammatory properties. Native American and Chinese herbalists have traditionally used black cohosh root for a variety of ailments, and as an insect repellent. This last property is responsible for the common name, bugbane. Currently, people use black cohosh as a dietary supplement for hot flashes and other menopausal symptoms. In 2014 consumers in the U.S. spent about $60 million on black cohosh supplements. Black cohosh contains potent phytochemicals that have an effect on the endocrine system. How it works is not yet clear. Further research is needed to assess its effectiveness as well as its long-term safety. Possible liver damage is one side effect that is under study. For more information on black cohosh studies, see the Source list at the end of this article.
Black cohosh offers a combination of ornamental characteristics that is both prized and difficult to find:
Black cohosh has small, numerous, creamy white flowers that appear in terminal inflorescences up to one meter long. With stem height, the blooms extend up to 2 meters in height, rising on wiry stems well above the foliage in late summer. Flowering commences at the bottom of each raceme and progresses apically (toward the tip). The long white inflorescences arch gracefully, lighting up the shady forest.
Black cohosh near Humpback Rocks Photo: Susan Martin
A few years ago while hiking on Humpback Rocks (Milepost 5.8, Blue Ridge Parkway), we came across a stand of black cohosh in peak bloom, which inspired me to add this plant to our shade garden. The plant’s height makes it a standout architectural plant at the back of the garden. Although most impressive when planted in groups, the plant can also add drama as a solo specimen plant.
Cultivation is easy if growing requirements are met: medium-to-deep shade, rich humusy soil, and adequate moisture. Leaf margins may brown (scorch) and growth may slow if soils are not kept consistently moist. Foliage generally does not need staking, but taller flower spires may need some support. Plants can be cut back to the ground in late fall to tidy the garden, if desired, but is not necessary.
Cohosh comes from an Algonquin word meaning rough in reference to the appearance of plant rhizomes. Plants can be propagated by rhizome division or by seed. To germinate, seeds require exposure first to warm temperatures and then to cold. Ripe seeds can be sown directly outdoors. Be aware that it may take years before plants reach flowering size. In the nursery trade, two varieties are usually available: dissecta, with deeply-cut leaflets, and cordifolia, with shallowly-lobed leaflets resembling maple leaves.
Flowers emit a sweet/fetid odor that attracts carrion-eating pollinating flies, gnats, beetles, and bumblebees seeking pollen and nectar. The plant is host for the Appalachian azure butterfly (Celastrina neglectamajor). Caterpillars feed exclusively on black cohosh flowers adults feed on flower nectar. Unfortunately, black cohosh is being forced out in some woodland areas by the nonnative invasive, garlic mustard (Alliaria petiolata). More information is needed on this threat.
Appalachian Azure, (Celastrina neglectamajor) Photo: pondhawk Wikimedia Commons
Black cohosh has no serious insect or disease problems. Rust and leaf spot are occasional problems.
SIMILAR PLANT – DOLL’S EYES
Black cohosh is closely related to doll’s eyes, also commonly called white baneberry (Actaea pachypoda). These two native perennials share similar characteristics and are difficult to distinguish based on foliage early in the season. As the season progresses, distinguishing characteristics emerge.
Doll’s eyes typically grows to 30” tall and is primarily cultivated in woodland and shade gardens for its attractive white berries and astilbe-like foliage. It naturally occurs in deep woods, north-facing wooded slopes, bluff bases, and ravines.
In spring, tiny white flowers appear in short, oblong terminal clusters atop long greenish stems rising above the foliage. The flowers lack nectar and provide only pollen to visiting insects. These visitors are mainly Halictid bees. Flowering stems thicken after bloom and turn an attractive red, as pea-sized white berries develop in summer in elongated clusters.
The berries are extremely poisonous if eaten, hence the common name of baneberry. Baneberry is the common name for several species of plants in the genus Actaea. This group in the buttercup family (Ranunculaceae) has toxic fleshy berries, hence the name “bane” meaning something that causes death or a deadly poison. Each doll’s eye berry has a distinctive small dark purplish spot (formed by the flower stigma) which is thought to resemble the eyes of old-fashioned china dolls, hence the common name. Berry toxicity is likely the main reason that wildlife seems to ignore the fruit, although birds seem to be immune to the toxins. Many species of native birds actually thrive on the plant. Such birds include the Ruffed Grouse, Yellow-Bellied Sapsucker, and American Robin. The White-Footed Mouse also eats the berries. Because the foliage is toxic from a cardiac glycoside, it is not eaten by mammalian herbivores.
Doll’s eyes Photo: Creative Commons
Self-seeding may occur in optimum growing conditions where the berries fall to the ground. If naturalization is desired, berries may be picked and immediately planted into the ground as soon as they ripen in the fall in order to promote colonial spread. It typically takes 2 or more years for seeds to germinate under natural conditions. Baneberry can also be propagated by division in early spring. Plants are slow growing and take a few years to grow large enough to flower.
Actaea pachypoda Photo: USDA, Wikimedia Commons
DIFFERENCES BETWEEN THE TWO SPECIES
In summary, A. racemosa and A. pachypoda share similar physical characteristics and are difficult to distinguish based on foliage early in the season. After flowering, there are distinctive differences:
Red baneberry Photo: Homer Edward Price, Creative Commons
There is also a red-fruited form of this species, red baneberry (A. rubra), distinguished by its thick floral stalk. Growing in bushy clumps, red baneberry bears fluffy clusters of small white flowers in spring. The berries that ensue in mid-to-late summer are brilliant red, though sometimes white, with a very small black dot at the end of the berry. This dot is less noticeable than the dot on the white berries of doll’s eyes. The leaves are alternate, compound, toothed, and more dissected than the leaves of doll’s eyes. All parts of baneberry plants, including the berries, are poisonous and should never be eaten. Red baneberry’s natural habitat reaches its southern limits in New Jersey, Indiana, Iowa, and Kansas.
Black cohosh brightens a shade garden with white flowers that appear on gracefully arching white terminal inflorescences up to a meter long. When massed at the back of the garden, the plant’s height and large astilbe-like foliage adds a strong architectural definition. It is the host plant for the Appalachian azure butterfly (Celastrina neglectamajor). Black cohosh’s position in the forest under-story, and its role as a food source for the Appalachian azure, is threatened by the nonnative invasive plant, garlic mustard (Alliaria petiolata). Doll’s eyes offers many of the same ornamental characteristics as Black cohosh, with the addition of attractive but highly toxic white berries.
“Herbs at a Glance: Black Cohosh,” National Institute of Health, National Center for Complementary and Integrative Health, https://nccih.nih.gov/health/blackcohosh/ataglance.htm
Black Cohosh, National Institutes of Health, Office of Dietary Supplements, https://ods.od.nih.gov/factsheets/BlackCohosh-HealthProfessional/
“Black Cohosh for Menopause Symptoms,” Michigan Medicine, University of Michigan, https://www.uofmhealth.org/health-library/tn9522
Appalachian azure, New York Natural Heritage Program, https://guides.nynhp.org/appalachian-azure/
“Baneberry, Actaea spp.,” Master Gardener Program Division of Extension, University of Wisconsin-Madison, https://wimastergardener.org/article/baneberry-actaea-spp/
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