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 beard tongue, 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.
Genus name comes from the Greek words penta meaning five and stemon meaning stamen in reference to each flower having five stamens (four are fertile and one is sterile).
Specific epithet means with off-white or ashy-gray colored hairs.
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.