High Plains Gardening
The gardening website of the Texas High Plains Region
‘Red Rocks’ is another hybrid cultivar, named for the Denver, Colorado red sandstone area and amphitheater. P. 'Red Rocks' is highly suitable for the average garden, rather than a specialized penstemon bed. Again, do not deadhead unless reblooming has occurred and you desire a tidier appearance. Don’t over water or over amend the soil, but it will thrive companionably with other medium water-use plants.
Near the front of a sunny bed or border for a midwestern or western cottage garden.
Snip spent flower stems at season's end.