I collected a bag of blossoms from the African Tulip Trees on the scenic drive on the way to Hilo. The trees are quite tall so I just used the blossoms that were on the ground. They all looked fresh and bright orange.
Then I soaked them in water for 16 hours, boiled them for 45 minutes and discarded the leaves. Meanwhile I soaked a silk chiffon scarf and a white cotton FQn in alum for maybe 45 minutes and then put both pieces in the dye pot and "cooked" them at 180F for 45 minutes. I removed the silk piece and raised the heat to boiling and let the cotton piece bubble away for another hour. Then turned off the heat and let it sit in the pot until the dyebath was cool. I rinsed and washed both pieces until the water ran clear and dried them in the dryer. The cotton, as you can tell from the photo, is significantly lighter than the silk, which I understand is typical for natural dyes. I based my process on Hawaii Dye Plants and Dye Recipes by ValKrohn-Ching published in the late 70s. The recipes in the book are for dyeing wool yarn but most of the instructions work with silk as well since they are both protein fibers. Gardenia leaves and bird of paradise leaves are soaking now so they will be my next experiment.