Ceanothus thyrsiflorus aka California lilacs are a species native to California and are drought tolerant.
Native Americans of California used the branches to weave baskets and used the dried leaves as a substitute for black tea.
They are very hardy shrubs which need ample water in the first year to get good root growth. After that, they don’t need much but a hair cut every now and then.
The blue flowers (on mine anyway) bloom in the early spring. They are also deer food. Some species are very fragrant (so I have read) however mine is not.
I use the flowers for healing spells and offerings. They germinate in fire and can lie dormant for hundreds of years. They are mostly used as ornamental plants for their flowers. Like most flowers, cut early in the morning when it’s coolest outside.
By summer they are flowerless with the occasional late bloomer which I always take as a sign of good health and prosperity.