The Rhodiola rosea has male and female plants so to get viable seeds I guess there have to be both sexes near each other, - that's life😍. Here we divide the plants or take root cuttings to propagate.
I also have another Rhodiola: Rhodiola semenovii (hope I'm spelling it right. That one is not native here and is rare in gardens. I was helping some people removing shrubs from their garden an they gave me this plant that nobody knew an I planted it in my country site. It really surprised me when it started to grow that spring/summer. There are photos of it in the database.
It is the second day of Christmas today and I'm having my family of 15 here tonight. Turkey already in the oven.😉