I tried growing a bunch of PNW native seeds in 2022-23. I got the seeds from Inside Passage.
I had good success with Castilleja miniata (giant red Indian paintbrush).
My basic protocol was to fill a sterilized 4″ pot with a soil-free mixture of 2 parts coir, 1 part perlite, 1 part vermiculite. I then planted the seeds and put the pots outside under a hardware cloth cover to get scarification over the winter.
Based on the UW native plant protocols (available to the public here: https://jbakker.shinyapps.io/Protocols/ ), I planted the seeds on the surface and sprinkled a light layer of perlite on top.
Note that you should be able to do scarification in the refrigerator; I’ll be experimenting more with that in the 2023-24 season. For my first attempt, I wanted to keep everything as “natural” as possible.
When I checked my native seed pots in mid February, I had some sprouts starting! At around this time, I brought the pots in and put them under grow lights in the garage (about 50F).
By 3/7 they had 2-4 true leaves, and I split them into multiple 2 and 4″ pots (scooping out small clumps of seedlings with a fork and transferring them as intact as possible), and added native yarrow seeds.
Most paintbrush species are hemiparasitic: they can do their own photosynthesis, but they get a boost from their neighbors. I had encountered a reference indicating that they could be grown with native yarrow, which is convenient because yarrow is an extremely fast sprouter.
The yarrow sprouted in less than a week, and they really started to take off.
I up-potted into 4″ and gallon pots over the next two months. I moved them back outside sometime in April, probably late April.
I got my first bloom at the beginning of June!
This was a lovely surprise, because I had thought that I would have to wait until the next year to get any blooms.
As it turned out, most of the Paintbrush plants wound up blooming, probably because of the boost they got from their time under grow lights through early spring.
Another unexpected and pleasant surprise was how long the flowers lasted. That initial flower was still going strong 3 weeks later. I think it lasted a good month.
The other paintbrush plants started blooming in late July.
Some paintbrush plants are biennial, some are perennial. I think these are perennial, so I will plant them out in a meadow area this autumn, and hope they come back next year.
One more planting note: these are listed as full sun, but we really don’t have full sun available; the best I could do was 6 hours of direct sun, with shade the rest of the day.
That probably wasn’t optimal, but it was enough to get blooming plants!
Let me know if you have questions! If you decide to give them a try, good luck!