Culture
Grow in average, dry to medium moisture, well-drained soil in full sun. Avoid wet, poorly drained soils.
Noteworthy Characteristics
Penstemon digitalis is a clump-forming, Missouri-native perennial which typically grows 3-5' tall and occurs in prairies, fields, wood margins, open woods and along railroad tracks. Features white, two-lipped, tubular flowers (to 1.25" long) borne in panicles atop erect, rigid stems. Flowers bloom mid-spring to early summer. Basal leaves are elliptic and stem leaves are lance-shaped to oblong.
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 comes from the Latin digitus meaning finger for flowers that look like the finger of a glove.
Penstemon is sometimes commonly called beard tongue because the sterile stamen has a tuft of small hairs.
'Blackbeard' is an upright, compact, dark purple-leaved selection of beardtongue that features pink flowers held on sturdy, dark purple stems. The blooms are highly attractive to hummingbirds and other pollinators. Mature plants will reach up to 3' tall with a 2' spread. 'Blackbeard' was selected as a seedling of Penstemon digitalis 'Pocahontas'. This plant is protected by patent number PP30052.
Problems
No serious insect or disease problems. Root rot can occur in wet, poorly-drained soils. Leaf spots are occasional problems. Can spread somewhat aggressively in a garden setting.
Uses
Mass in sunny borders, native plant gardens or pollinator gardens.