I have a fremontodendron that is dying. It appears to have sent up 8 root shoots up hill, where the main root was nicked during an invasive bamboo removal nearby. I found your post, and then found some information on summer hard-wood cuttings on the Royal Horticulture Society website. Here is the link, if anyone is still interested in vegetative propagation by mallet cuts best taken in summer season (after bloom period) - while this plant is in its summer dormant state.
https://www.rhs.org.uk/Plants/...
If I have any success, I will post photos of my experiments.
