Penstemon strictus is evergreen with multiple spires of large, violet-blue, tubular flowers designed, as with all Penstemon, with the hummer in mind (and I don't mean the SUV!). This one will tolerate heavy soils better than some, but "tolerate" is the operative word, preferring well-drained gritty soil. It's profuse in the Four Corners region, Mesa Verde, and low-elevations of the Rockies.
Mature size: 1 – 3 ft tall and wide.
Minimum temperature: -40° F