I have germinated this seed, as I grow it in my yard and it produces quite a lot of seed, unlike A tomentosa. It takes time. I would soak the seed overnight in warm/hot water and then put in damp sand (I use desert sand) and stratify for 4-6 months. Then you will want to take it out and leave it in the sand and put in a warm area for several months. Do another stratification for 4-6 months, and then you should experience germination. It takes 2 winters for seeds to germinate. You can also direct sow, and it will come up. It's very slow. I have the best results letting the seeds fall to the ground and leaving them to germinate on their own.
It has been a great host plant for the Pipevine Swallowtails here in NE OK. Needs shade in the heat of the summer.
