Engelmann Oak is a stunning, evergreen tree with bluish, gray green oval leaves. It is known to go semi-deciduous in the warmer months when there is drought, but the leaves should spring back after first rains. This under-rated and under utilized plant only grows in Southern California, so it should be more widely used in our landscapes. Despite what most people think of Oak trees, the growth rate is moderate rather than slow, assuming you give it consistent weekly water.
We try to get these plants in every install. They create a very elegant natural shape, but do require some removing of branches for better air flow. Beware not to prune too much. When the plant is young, be sure not to completely remove the lower branches. The young tree uses the low branches as a balancing support system. Best to let this grow as a screening tree/shrub for the first 7-10 years at least.