Penstemon grandiflorus Commonly known as Large-flowered Beardtongue, Large-flower Penstemon, Large Beardtongue, Large Penstemon Penstemon grandiflorus is a herbaceous perennial native to sand prairies, tallgrass prairies, loess hills, and other open, grassy habitats. Mature plants typically grow 2-4' tall and are noted for their upright growth habit, large, tubular, blue-lavender flowers, and silvery foliage. Flowers (to 2” long) bloom in upright, open racemes in late spring. Foliage consists of thick, toothless, opposite, clasping, blue-green leaves, with the basal leaves obovate and the stem leaves rounded to elliptic. Best grown in gritty, dry to medium, well-drained soils in full sun. Avoid moist, poorly-drained clay soils. Do not overwater. Full sun may help avoid onset of root rot. Plants may be cut back to basal foliage after bloom to improve appearance of the planting. Plants will self-seed in optimum growing conditions. Height: 2'-4'Spread: 1'-1.5'Bloom: May-JuneLight: Full Sun-Part ShadeWater: Low-MediumZone: 3-9Origin: Texas, Central U.S.
