I have a dark-green-foliaged one with darker blue flowers, called First Choice. I like the flower color best of all of the Caryopteris. It's definitely blue, not purple, and darker than the standard Longwood Blue (I'm not sure I got that name right). I have yet to find out if the stem length is any better. They went in as bareroots last spring and are enduring their first winter right now.

Jeanne

Caryopteris really appreciate being mulched during our harsh winters.
First Choice and Longwood Blue have already been mentioned. These choices are good for you in zone 6-9. Not good for us Michiganders.
Also, check out Dark Knight. These are all available from Walters Gardens along with the Sunshine Blue.

Yup, that's where I got my First Choice plants from! I'm in zone 5, though, not 6. In fact, my primary growing field has a zone 4 microclimate, due to a cold-sink problem, but the caryopteris is in a warmer, more sheltered area.

I tend not to mulch anything because our long, cold, wet, dramatic-temperature-swing springs and autumns tend to cause anything that is mulched to rot, especially plants that prefer dryish conditions - like caryopteris, for instance.

I didn't go for Dark Knight because the only description I could find made it sound more purple than blue. I already have all the purple I can stand. Do you know what color it really is?

Jeanne

I don't know why Walter's Gardens said they are zone 6-9. We are also zone 5; and, I drive by their fields. Maybe just to play it safe.
The Dark Knight seemed to be a deeper purple blue.
Now Jeanne you know that purple looks good with your favorite color orange!!!!

The Caryopteris "Sunshine Blue" already sold out at Walters.

Believe it or not, I actually do make purple and orange bouquets, usually with some yellow or white or both added. I can't stand them myself! - but they usually sell, if I don't make too many of them. But I do have way too much purple. It's one of my favorite colors. I took a vow a year ago not to acquire any more purple perennials until the rest of the colors got caught up. It's going to be awhile.

Jeanne

The two best Caryopteris - Petit Bleu which has dark flowers, glossy dark green leaves and a full compact habit. I've compared it side by side with Dark Knight, Grand Blue, and First Choice and think that it beats them all.

Sunshine Blue is a new golden leafed form of incana that blows Worcester Gold away.