Blue Cohosh (Caulophyllum thalictroides)

Blue Cohosh, or *Caulophyllum thalictroides*, is a native perennial herb in Eastern North America. Known for its distinctive blue-green foliage and small, bell-shaped flowers in early spring, Blue Cohosh has been used as a coffee substitute (reportedly) despite it's possible toxicity.  It can be difficult to germinate and spread, but once established will need little care. This plant is used medicinally by many Indigenous peoples, for uses relating to women's health. The colour of the plant changes depending on when in the season.

It is sometimes grown as a speciality crop. Overharvesting in the wild is a big threat where Blue Cohosh is in trouble (Manitoba and some States) as it can take multiple exposures to winter to germinate. so it isn't a fast growing plant and can't keep up with the demand.

## Colour Change

   Blue Cohosh has an Indigo coloured form, but it wasn't clear to me if this was as an early bloomer (some sources implied this) or if you have to buy the correct type. More research needed.

## Benefits

### Uses

Indigenous, Medicinal, Shade Gardens, Wildlife Food source, Early Pollen/Nectar Source

## Sowing and Reproduction

There is no gender requirement to grow *Caulophyllum thalictroides.* The plant is bisexual and pollination is all it needs.

**Method**

Immediate sowing in Fall is recommended, but can be artificially stratified or sown using the 'winter-sow' container method. Sow just under the surface. Some sources suggest scarification  and others suggest removing the seed coat for best germination.  **GA3 and other treatments have no effect on it's germination.**

**Cold Stratification**

*Caulophyllum thalictroides* is known to be difficult to germinate and requires Double Dormancy or more. While you might get lucky and have it germinate the first year, some people have found it can take even 3 years or more! It requires repeated cycles of Cold and Warmth to pull it out of it's deep dormancy, so it's best stored moist in the fridge or sown immediately.

## Harvesting

Seeds can be collected from Blue Cohosh's distinct berries anytime after they turn blue. Early collection can make it easier to germinate.  Since Blue Cohosh is toxic wear gloves and DO NOT eat the berries.

## Storage

Removing the flesh of the berry is essential for storage. Like other berries it will prevent germination and cause problems over time. In nature this is done by squirrels and other animals who break down the organic matter after eating it and excrete the seed. There are multiple methods we can use such as putting it in a food processor, or soaking and hand removing the berries.

Blue Cohosh seeds MUST be stored moist unless they are being planted immediately in fall. If they dry out, germination will be very low as many seeds will die. Store in moist vermiculite or sand until sown.

## Toxicity

**Strength:** Low, depending on how it is taken (via skin, orally etc).

**Toxic to:**

* **Humans:** Though used as a coffee substitute and herbally, Blue Cohosh is thought to have a Low Toxicity when ingesting seeds and roots. The raw berries are thought to be poisonous to children. Avoid eating.
* **Dogs and** **Cats:** Exact effects are not widely known, but will cause at the very least an upset stomach. Considered toxic to both dogs and cats.
* **Livestock:** Unknown, but given the toxicity, recommend to avoid.

1. ↑ 1.0 1.1 LadyBird Johnson Wildflower Centre Plant Database
2. ↑ NC State Extension
3. ↑ Wikipedia
4. ↑ United Plant Savers
5. ↑ 5.0 5.1 Everwilde Farms
6. ↑ Iowa State University
7. ↑ 7.0 7.1 7.2 7.3 White Oak Nursery
8. ↑ Botanically Inclined
9. ↑ White Oak Nursery
10. ↑ By Eric Hunt Creative Commons License 4.0
11. ↑ Sweeten Creek Animal and Bird Hospital