Pineleaf Penstemon in the Landscape
Stephen Love, University of Idaho
Scientfic Name: Penstemon pinifoliusCommon Name: Pineleaf Penstemon
Description: Pineleaf penstemon is a long-lived perennial with woody branches and semi-evergreen foliage. The plant is relatively small in stature, usually only 10 to 15 inches tall. The branches are numerous and form a dense mound. The leaves are very small, needle-like, and spaced densely along the stems. The flowers are numerous, fairly small, tubular, and dark red. The bloom period is very long, lasting from mid-June until late August. Pineleaf penstemon is a good subject for rock gardens, beds, and borders.
Native Habitat: Native to southeastern Arizona and southwestern New Mexico. Grows on cliffs and open rocky slopes at elevations of 5,000 to 10,000 feet. Often found in fir, spruce, and pine communities.
Cultural Requirement
Soil: Adapted to a range of soils, including those with high pH. Lifespan is greatest when grown in well-drained sandy or gravelly substrate.
Moisture Tolerance: Moderately xeric but requires some supplemental irrigation to remain attractive throughout the season.
Sun/Shade/Preference: Requires full sun for best bloom.
Transplanting: Tolerates transplanting well, both from pot to pot and from pot to garden. Plants develop well and look good in pots up to one gallon in size.
Propagation: Best from seed. Germination is enhanced by a 4 to 6 week cold stratification period. Also amenable to propagation as rooted cuttings.
Maintenance (pruning, fertilization, deadheading, division, irrigation, etc): Removing stems with spent flowers will often encourage prolonged bloom. Supplemental irrigation is needed (three to five times during each summer) to keep plants actively growing and attractive. Only occasional, minimal fertilization is needed, as plants demand.
Insect, disease, or other problems: Pineleaf penstemon has no serious insect or disease problems.
Landscape Value
Use in the Landscape: Pineleaf penstemon is a mounding to spreading plant. It is suitable as a specimen plant, either alone or among other short plants in beds, borders, or rock gardens. It can be used in either naturalized or formal designs.
Foliage: The leaves are medium green, small, narrow, and look like short pine needles. Mature plants produce numerous leafy stems.
Flower: The flowering stems are short extensions of the leafy foliar stems. The flowers are about one inch long, bright red, tubular, with long narrow lobes.
Timing: June - August.
Color: Red, rarely yellow.
Fruit: A small, upright, globular capsule, with sharp, stiff lobes on top. Each capsule holds numerous seeds.
Form: Loosely mounded to spreading.
Texture: Moderately fine.
Ultimate Size: In bloom – 6 to 8 tall; prior to bloom 10 to 15 inches tall. Width similar to or slightly greater than height.
Rate of Growth: Moderately slow. The plants rarely bloom the first year. The plants increase in width and number of flowering stems as they age.
Suggested Plant Partners: Plant pineleaf penstemon with low-growing forbs and grasses or in front of taller plants. Blue fescue (Festuca idahoensis) is a great complimentary plant. Other good partners include dwarf silver forms of Ericameria nauseosa, Erigeron coulteri, Melampodium leucanthum, Salvia azurea, and Zinnia grandiflora.
Availability: Easy to find as a potted plant at local or mail order native plant nurseries. Occasionally available at traditional nurseries. Seed can be purchased from the American Penstemon Society or from some native plant seed suppliers.
Cultivars: 'Baby Firecrackers', 'Iron Man', 'Mango', 'Shades of Mango', 'Tangerine Select', 'Wisley Flame', and two rare yellow forms are available as cultivars, 'Mersea Yellow' and 'Magdalena Sunshine'.
References:
Busco, J. and Morin, N.R. 2003. Native Plants for High Elevation Western Gardens. Fulcrum Publishing, Golden, Colorado.
Nicholls, G. 2002. Alpine Plants of North America: An Encyclopedia of Mountain Flowers from the Rockies to Alaska. Timber Press, Portland, Oregon.
Nold, R. 2008. High and Dry: Gardening with Cold Hardy Dryland Plants. Timber Press, Portland, Oregon.