I think (?) just a few days for each flower but the plant makes several flowers. Ran out into the back yard and the petals have fallen off one set of flowers and yellow is showing on the next bud. I never timed it but looking back through my images of the plant the dates range from March 25th to April 28th so at least a month of color I guess. The seeds are easy to collect.
I still call them by their other name Helianthemum carolinianum; can't get used to saying Crocanthemum carolinianum. Still sorting stuff since I moved house but when I finish sorting my seed stash I'll let y'all know if I have seeds to share.
