Looks like Matthiola incana to me common name Stock, if so it likes sun and moist well draining soil. Plant seed in spring to bloom in summer.
Nice fragrance, why I don't have them in my garden is a mystery. In warmer climes it will overwinter, it's a member of the cabbage family.

Annette

I'll second that.
What a beautiful color.

Mine didn't come up or grow this summer. Maybe next year.
~Annie

I love stock...especially the double blooms. They do best in our area, in spring/early summer with a little afternoon shade. They often rebloom in the fall...very similar to alyssum that way. They can both take a little frost, too, so I buy them both in the early spring as transplants and put them out in the front gardens. They look great with the roses :)

I can't find stocks here, well, most of the time anyway. And then, they aren't the tall ones I love. Same with Snapdragons. The ones they sell here of both plants are short. One nurseryman told me it is because of our strong crosswinds - they tend to blow the tall plants over. I told him, that's what garden stakes and twist ties are for! :)
But, we do get a pretty good variety of Sweet
Allysum, although white is my favorite. It shows up more as a border plant. And most years they reseed themselves.
I bet your flowerbeds are gorgeous, Lavender_Lass!

I would imagine that stock could be perennial in CA. It would be worth splitting that rootstock, cutting down the spent flowers and planting the pieces out. I think you could get at least 3 or 4 plants from what I can see there. It will also grow from cuttings and there are a couple of likely looking shoots on those flower stems. That way you will get exactly that colour. If you sow the seeds you may get a variety of colours.