I know this is an old thread (I was searching for something and saw your post). If you haven’t found out by now, I know exactly what your mystery plants are:
Those are Mexican Evening Primroses. I know b/c I grow them in my Southern California garden. They will spread out over the years and might become a pest. I love them and think they are beautiful. Hope you enjoy them too. They take very little care.
thanks for your post!
How they drifted into my little garden in MA is a mystery! But they looked great for almost a month - they were fading out this week and then some varmint ate off all the flowers and tops of the stems!
I’ll move them over to my slope where I need some ground cover - they can spread to their heart’s content! By the time they become pestiferous, I’ll be outta here..