[2] The stems are covered in extremely fine and short hairs that increase to being glandular and hairy closer to the buds and flowers, but are rarely almost or completely hairless.

[5] The flowering stem is a thyrse, it grows without a genetically determined limit, but instead stops due to environmental conditions.

Close examination will show that the flower clusters are actually paired groups on opposite sides of the stem (a verticillaster), but they will face in every direction.

The flower is a tapered funnel 10–16 mm long and pale sky blue to light purple or violet.

[15] Penstemon virens is commonly found growing on rocky slopes, on rock outcrops, in forest openings, along road cuts, and other disturbed areas.

[18] Penstemon virens tend to grow together in large numbers rather than singly or scattered throughout the landscape, rarely fewer than 10 plants in a population.

[21] Penstemon virens was evaluated as a potential host for Castilleja integra and was found by the researchers to not support this partially parasitic plant for more than a few weeks.

[22] Blue mist penstemons are recommended as garden plants by local governments,[23] water providers,[24] and extension services[25] for areas in or near the Front Range.

They are prized for their low water usage, adaptation to local climate, handsome blooms, long lifespan, and ease of cultivation.

[5] Dr. Dale Lindgren of the University of Nebraska writes that their seeds require cold and moist stratification of six weeks at 4.5 °C for good germination rates or to be planted outside over the winter.

[5] However, experiments by Dr. Norman C. Deno indicate that period of dry warm storage of around 21 °C (70 °F) for six months before cool moist stratification is critical.

His research also showed that seeds left in the dry stems after ripening accomplish the same effect in natural settings.