My rockrose is sprouting like crazy this year, right now there are many little plants growing. I can't say why. I've had it growing in the same spot for about six or seven years now and let the seeds fall but it's never sprouted so much before. The seed must be good, if you'd like me to send you some to try. Or, I can dig some of those sprouts up and send to you.
Send me treemail and let me know.