Blue Blossom
Ceanothus thyrsiflorus
This California Lilac is endemic to California. There are many cultivars and Hybrids from this, but the original Blue Blossom has a very soft blue flower. In habitat it has been known to grow about 20 feet tall, but in local gardens it stays under 12ft. generally.
The small native bees can live off these flowers. But be warned – the deer like these soft green leaves too.