Grow Black Cohosh to Harvest its Medicinal Roots

Black cohosh is one of the best herbal remedies for women. This medicinal plant can treat pre-menopausal and menopausal symptoms, as well as help with fertility issues and induce labor at the end of pregnancy. This herb can also help with vertigo, night sweats, sleep disturbances, nervousness and irritability. Why not grow black cohosh at home?

What is Black Cohosh?

This perennial herb is native to North America, where it grows wild in the marshy forest that ranges from the Great Lakes to the Appalachian Mountains. Native Americans used this plant for medicinal purposes and introduced it to the European colonists, who began to use it as well. Black cohosh has many medicinal benefits, but it is a strong herb so it should be used with caution.

As a herbaceous wildflower, black cohosh needs shaded growing areas. It is a member of the Ranunculaceae family, Cimicifuga reacemosa, and has many colloquial names including black bugbane, snakeroot, and rattle weed.

Some like to grow black cohosh because it is a very pretty plant with wispy plumes of white flowers which can attract pollinators. This plant can grow quite tall, from five up to eight feet. It is possible to buy seeds from specialty seed merchants. But it is best to grow black cohosh from rhizomes.

grow black cohosh

Grow Black Cohosh from Seeds

Start your seeds indoors or in a greenhouse in the fall. Seeds need to go through a stratification process to grow black cohosh, which means that they need a cold-warm-cold cycle before germinating. Stratify them indoors to control the process about four months before you plan on planting them outside. Black cohosh seeds need to be exposed to 70F (21 C) for two weeks. They can be placed in a closet with a heater. Then they need to be at 40 F (4 C) for three months, which is easy since you can put them in the refrigerator.

Seeds may take up to two years to emerge, so if you plan to gro black cohosh from seeds keep in mind it is not the easiest or fastest way. If you do manage to get seeds directly from a black cohosh plant in the fall, then you can plant them outside right away. Nature will stratify them and germinate them in one or two years.

Plant seeds in the garden or indoors about 1/4 deep and at least 2 inches apart. Cover with a 2 inch layer of leaf mulch and water well. Keep the soil moist until the seeds germinate. Wait until spring to transplant outdoors if you started your seeds indoors. Wait until they have at least two sets of leaves and make sure to harden plants for one week.

Grow Black Cohosh from Rhizomes

Some seed producers sell rhizomes online and they may be found locally depending on where you live. This is a more efficient way to grow black cohosh. Cut the rhizomes into pieces that are about 4 inches long and have at least one bud. Leave any fibrous roots as well.

Plant rhizomes 4 to 6 inches deep with the buds pointing up. Cover them with at least 2 inches of soil and 3 to 5 inches of leaf mulch.  Keep the soil moist and add more leaf mulch as it decomposes.  Keep in mind that black cohosh will spread over time. Grow black cohosh by planting rhizomes can be planted 20 inches apart.

Black Cohosh Growing Conditions

This temperate plant can grow in USDA zones 4 to 9. You can grow black cohosh as long as you can get the soil and water conditions that it needs. Soil should be well draining but it can stay moist. Dig a lot of well-rotted organic material to make it similar to a forest floor. Keep mulching with leaves as needed. Black cohosh will not grow in clay or compacted soil.

Black cohosh grows in dense woodlands under canopies. Therefore it needs shade with only a little sunlight. It is best to try to mimic the natural growing environment of this plant. Too much sun will stunt it and turn the foliage pale green. Apply a slow release fertilizer during the spring if the plant appears stunted.

It is not possible to grow black cohosh in pots since it has very large roots. However, it can be planted in deep raised garden beds that have rotted organic material. This herb can handle partial wet roots, which makes it suitable for planting on the margins of waterways. Keep the soil moist but not soaked. Ideal soil pH ranges from 5.1 to 6 which is more acidic.

Prune back in the spring which makes the floral display even better. These gorgeous white flowers are often the last ones left in the garden in the fall and winter. Stalk fall flowers if they are growing in windy areas.

Grow black cohosh with suitable companion plants including other medicinal woodland plants such as wild ginger, American ginseng, Goldenseal and Solomon’s seal.

Black Cohosh Pest and Diseases

This medicinal plant is usually quite healthy, however it does have some problems with pests and diseases. Avoid overwatering when the plant is young so it will not damp off, which means that the stems and roots of the plant rot because of a fungal pathogen.

Leaf spots can be seen when spots form in the leaves. These spots have light centers and dark edges. This is another fungal problem which is caused by too much moisture and not enough airflow. Make sure there is enough space between plants so they can get good circulation. Cut affected leaves before the fungus spreads. Use a mixture of baking soda and water to spray liberally. Otherwise use a copper based fungicide or sulphur fungicide.

Cutworms are the caterpillar of night-flying moths. They come at night to cause problems in the garden because they eat the stems at ground level. Blister beetles are another problem that can affect when you grow black cohosh plants. They eat the flowers, leaves, pollen and even other insects. Birds can pick off the beetles. Otherwise use organic pyrethrum to control them.

Rabbits, opossum, and deer also like to eat this plant so fencing or repellents would be needed to control them. Slugs and snails also like to chew on black cohosh foliage. Use sawdust, eggshell, beer traps or copper tape barriers to control them.

How to Harvest Black Cohosh

The best time to harvest black cohosh is in the fall because the roots are in their peak. Pull up the plant by hand so the entire root system and rhizomes come out of the ground. Save any rhizomes you need and plant them right away. It is also possible to store them up to a year in burlap sacks in a temperature of 40 F (4 C) with good circulation so they don’t rot. Fresh rhizomes should be kept with moist sphagnum moss as well. Stir the roots occasionally to promote ventilation and to prevent the growth of fungi.

Remove all soil, rocks, and sand that can be stuck to the rhizomes by washing them by hand or in a root washer. Once the roots are clean they can be dried using low heat with constant airflow. Use a food dehydrator o a specialized herb dryer for better results.

If you grow black cohosh from rhizomes you will be able to harvest in three years, while it will take between four and six years if you start your plants from seeds. Some states in the United States prohibit the selling of this herb because of “over-harvesting and selling” so make sure it is legal before trying to sell black cohosh.

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