Shrubby penstemon is unique in that it has a sub-shrub habit featuring a dense creeping mat of foliage. The evergreen leaves are somewhat leathery, and when it flowers the whole plant can appear to be covered in large blue or purple trumpet-shaped blooms. While it won't get very tall, this species can get to several feet in width.
 
This species has an affinity for dry rocky slopes, and its trailing stems will sort of flow around and down the rocks. Although it can tolerate full sun, it will do best with some protection from intense afternoon heat.  Consider placing some rocks (football size or so) near it to provide some shade and protection. It requires well-drained soil (like a slope).  
 
Some penstemons can be short-lived if the soil is too rich. Avoid excessive compost (our native soils should be adequate). 
 
Alumroot, sticky cinquefoil, jacob's ladder, and Oregon sunshine are all good neighbors for this penstemon.
 
 
 
Image credit: Walter Siegmund (talk) - Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=3047387