I haven't done it yet, but yes, will zap some info here.
Quick find https://lacreativemama.com/natural-dyeing-goldenrod-flowers/
Best bet if you want to try it is a good natural dye book from
https://portfiber.com/
You can ask Casey about it. Thry slso host classes there.
A master natural dyer lives out on Peaks too and gives classes lots of places. Will look.