Culture
Easily grown in average, dry to medium, well-drained soils in full sun. Avoid wet, poorly-drained soils. Remove spent flowering racemes to prolong bloom. Plants may be cut back to basal foliage after flowering to improve appearance of the planting.
Noteworthy Characteristics
Penstemon canescens, commonly called gray beardtongue or Appalachian beardtongue, is a clump-forming perennial which typically grows 1-3' tall. It is native to dry slopes and woods primarily in the Appalachian Mountains from Pennsylvania south to North Carolina and Alabama. Features loose terminal racemes of pale to dark violet, two-lipped, tubular flowers (to 1 1/2" long) atop erect, rigid, hairy, gray stems. Flowers bloom in late spring to summer. Clasping, oblong-lanceolate, medium green upper stem leaves (2-6" long). Broad-ovate basal foliage. This species is often covered with dense, minute gray hairs.
The genus name Penstemon likely comes from the Latin paene meaning "almost" or "nearly" and the Greek stemon meaning "stamen". The name may also comes from the Greek penta meaning "five" and stemon meaning "stamen". Both refer to the fifth, sterile stamen (staminode) that characterizes members of this genus.
The specific epithet canecens means "with off-white or ashy-gray colored hairs", in reference to the stems of this species.
The common names of this species refer to the color of the stems and its native range. Penstemons are sometimes commonly called beard tongues because the sterile stamen has a tuft of small hairs.
Problems
No serious insect or disease problems. Root rot can occur in wet, poorly-drained soils. Leaf spot may also occur.
Uses
Sunny areas of borders, rock gardens or native plant gardens.