Watering every two weeks seems too dry regardless of what potting mix is used. I would increase the watering to once a week. It's sad that the flowers wilted and stopped blooming but I wouldn't worry about it. Trim the flower stem down to the top leaf when you are done looking at the flowers. Then, place the plant in some filtered direct sun. When you see new growth from the base, increase watering so the plant stays at least slightly moist but well drained.

Thanks bboy! Glad you identified this sucker, esp since the seeds are viable for 50 years... YIKES! Gonna get these just in time though. Looks like they're edible, so I'm gonna try stir fryin' some leaves up tonight. Thanks again!

Mmm. This time I'll suggest Caryophyllaceae and leave it to nonmember to clear up the wreckage left by someone speaking from zero knowledge. Oh, all right then, I'll have a go. Agrostemma githago? Is that a possibility in Ca?

Using your genus tip I think it might be Hypericum punctatum (Spotted St. John's-wort). Also looked at H. mutilum and H. boreale but the leaves seemed too small.