Rhamnus purshiana seeds (Cascara sagrada)

Description

PNW medicinal tree.  A lovely tree with deeply veined leaves.  In May the flowers are alive with bees.  In June-July birds swarm the trees to feast upon the fruit as it ripens from green to glossy black.  I’m lucky to get any seeds. USDA recognizes this genus as Frangula not Rhamnus.

Cascara sagrada, translated from Spanish, is “Sacred Bark” as  properly aged bark is/was used medicinally as an effective laxative.  Its valuable bark was harvested without much thought of the future as soon the plant became rare.  Use with caution.

On one of my late winter walks someone erroneously mistook a cascara for one of our big leaf maples and tapped it for sap to make maple syrup.  I had to smirk knowing the situation in the collector’s household were going to get very interesting.

• Seed Count: 20-25
• Collection Date:  July 2024
• Hardiness Zone: 3b-8
• Height and Width: 6m x 6m
• Preferred conditions: Full to semi sun; humus rich acidic soil
• Germination test type: float
• Family: Rhamnaceae

How to germinate Rhamnus purshiana seeds:

Soak seed 24 hours.  Cold stratify (2C) in moist medium for 90-120 days.  Give gentle warmth to germinate.  Judging from the stray seedlings around here, germination can be quick.  Usually an under-story tree but it springs up everywhere.  Just don’t let seedlings dry out.