3 years ago I was in a park in London and saw a marvellous display of some kind of caryopteris. A sheet of vivid blue. I wrote the the local parks department but they weren't able to help with name. I have tried with various ceanothus plants without success. Lack of success was, I suspect, needing to water the plants as they were in pots and the combination of water in high temperatures. A common killer of Californian natives. Caryopteris, I decided, might fill the gap.
I have managed to find 3 different plants
Caryopteris x clandonensis heavenly blue (first 2 photos)
For me it is a bit of a disappointment. Leaves comparatively small, straggly growth. Occasionally wilted in the intense heat of summer. Started to flower about 3 weeks ago.
Caryopteris 'Grand Blue' (3rd and 4th photos)
Larger leaves than above and denser foliage. Fuller appearance and more flowers. Occasional wilting in extreme heat. Came into flower last week.
Caryopteris incana (last 2 photos)
Largest leaves of the 3. Dense and dark foliage very attractive and a little more compact than the other 2. Has never show signs of wilting. This would have been the clear winner except for the fact the flowers came through pale pink! I wasn't expecting that to happen and rather spoils the "shades of blue" thread. The buds looked white while they were developing which was a nice contrast to the dark leaves. They took a while to develop. It came into flower last week.
All 3 are very attractive to bees.