Yampah is group of perennial plants in the genus Perideridia that produce edible tuberous roots. There at least a dozen species native to the western half of North America.
I started growing yampah from seed in fall 2018. Five years later, everything in my collection is flowering.
The species I am growing are:
Perideridia californica - Native to the coast ranges in the southern half of CA. Reputed to have the largest roots of any yampah.
P. bolanderi - Native to the Sierra Nevada, as well as other western states.
P. gairdneri - Native to CA, east to the Rocky Mountains, and north into Canada.
P. kelloggii - Native northern CA. Doesn't usually make tuberous roots, but may still be useful for breeding since it can have large clusters of roots
Mass cross of P. gairderni, bolanderi, and oregana from Bill Whitson.
Perideridia californica has so far proved to be superior for me. It had the best germination (fall sown with no extra stratification), least seedling die-off, fastest growth, and earliest flowering from seeds.
My goal is to select for better root prodution. This is a slow process for a perennial plant that takes several years to mature from seed. Sometimes I wonder if this project is worth my time. But this year everything is flowering despite a fair amount of neglect, growing in too small pots, and plenty of time wondering if the dormant plants are really all dead. I think by now these yampah plants have proved themselves to be worthy of my time just for their impressive resilience.
After I harvest seeds this summer I plan to take a look at the roots and pot the best ones up into larger pots. Hopefully I will continue to produce seeds every year that I can trade around to other people interested in growing and breeding yampah.
My little yampah collection starting to flower.
Perideridia californica is the first species to flower.
Two year old Perideridia californica roots. These were all crammed together in the little pot where I sowed the seed. The ones on the right in the photo had died.