Coo season annuals mean just that; that they prefer cooler springtime temperatures to hot summers. They generally fade out once the heat hits, although you might have a couple of troopers that hang in there for a few weeks. The blooms are never the same as when they first start, though. Snapdragons, pansies, and many of the ones you mentioned are cool weather annuals.

It also depends upon where you have them planted; while they may not stay around most of the summer, they last longer if planted in sheltered or partly shady conditions. Containers, though, heat up fairly fast; and you are wise to choose some summer heat lovers. Zinnias and dahlias, sunflowers and some roses like some heat. Succulents do too; and some summer bulbs don't mind a sunbath, either. Petunias tend to do well in higher temperatures, so can cosmos.

Thanks, Hopflower - could you tell me, though, which of the ones I mentioned are Cool-Season? Or would it be all of them. I grew coreopsis once when I lived in Sacramento, and it was fine, although it had a bit more afternoon shade than this tub will have. I'm guessing that the cornflower and the campion are among the cool-season crowd (they sound English!), but I don't really have a clue. The zinnias and dahlias would probably grow well here...the tub will have some shade in the later afternoon, but in high summer, the sun will be directly overhead until then. I think maybe I didn't really think this through (also had some misleading advice from a relative...). Probably at this point I need something that I can find already growing at a nursery.

I know the bachelor buttons are cool-season annuals. I'm not sure about the others, except that coreopsis should be fine. It's a good summer flower.

In the Central Valley, you may have to worry about the humidity causing powdery mildew on zinnias and dahlias. I definitely failed at dahlias when I lived in Sacratomato. But I did grow zinnias OK, although some would get mildewy.

Thanks, Stevation - I'm glad to know about the mildew thing in regard to zinnias and dahlias. I was sort of thinking about them, though neither of them would really look right in the surroundings. I tend to think of the Central Valley as not having a problem with humidity, but I suppose it does...I know that one of our roses (a gorgeous Climbing Peace) gets mildew, though not so bad that it becomes a big problem. It's looking fabulous right now. Maybe I'll get some yellow coreopsis to plant with the maroon that I have coming on. Or maybe I'll just go to the nice nursery people up in Turlock and throw myself on their mercy.

Cornflowers are cool season annuals, yes. Dahlias and zinnias tend to love the heat. But some roses do, too. A thought is to use Ortho's Rose Pride, which helps against disease, mould, mildew, and insects; and also feeds the roses systemically. I use it and rely on it to both feed and protect my roses. It is applied about every six weeks.

Generally speaking most annuals you find in early spring are those that do best througut the cool temps. The others are brought out slowly because they do not germinate when it is too hot; or if they do, do not grow adequately until the heat hits.