This is a cool (even COLD) season plant. As a matter of fact, stock belongs to the same plant family as our favorite cold season veggies such as cabbage, kale, broccoli, and others. I sure wouldn't plant it in the beginning of the hot season.

Yes, it is a very cold season plant. The first time I grew it, I grew some from seeds. They last till snow. In fact, they last so long that I thought they might remain evergreen through the winter. Finally near the end of the winter, they died.

I know I'm super late on this thread - I found it in a search but I just bought a bunch of these instead of snapdragons because they had beautiful colors and were on sale at HD in late March this year. Our temps in Venice never really go below 50 and are definitely hotter than 60 and they are still going. If I remember, I'll update this thread when they stop flowers.

I would love to know if they come back as I heard certain annuals behave like perennials or are even evergreen due to our warmer climate here.

No annuals do not act like perennials. Perennials will often be grown as annuals in climates too cold for them. In your climate SoCal both stock and Snapdragons can be grown flowering right through your winter, as they do here. I take mine out by the first of May, still blooming but getting ragged looking. Neither are annuals. Al