Penstemon whippleanus
Whipple's penstemon
Rocky Mountains, western North America
Overview
Penstemon whippleanus is an upright perennial in the plantain family, growing 8-28 inches (20-70 cm) tall from a basal rosette on one or more leafy, often dark-tinged stems. The opposite leaves are lance-shaped to oval, 1-4 inches (2.5-10 cm) long, smooth-edged, and stalkless on the upper stem. In mid to late summer it bears nodding, tubular two-lipped flowers 0.8-1.2 inches (20-30 mm) long in tiered whorls toward the stem top, most often a deep wine-purple to dusky maroon, though cream and pale lavender forms occur. The inflated throat is hairy within, and the lower lip is bearded, guiding bumblebees and hummingbirds to the nectar. Dry capsules follow, splitting to release many small seeds. It grows in subalpine and alpine meadows, open conifer forest, rocky slopes, and clearings of the Rocky Mountains, generally at 7,000-12,000 feet (2,100-3,700 m). Cold winters, sharp drainage, and bright mountain sun are its normal conditions, and it struggles in heat and humidity at low elevation. The dark, hooded flowers and high-country habitat make it easy to tell apart from lowland penstemons.
Native Range
Native to the Rocky Mountains of western North America, from Montana and Idaho south through Colorado and Utah to Arizona and New Mexico. It grows in subalpine and alpine meadows, open spruce-fir forest, and rocky slopes, mostly between 7,000 and 12,000 feet (2,100-3,700 m). Its range follows the high country of the central and southern Rockies.Suggested Uses
Penstemon whippleanus is used in rock gardens, alpine and trough plantings, and native mountain meadow gardens in cool climates. Its dark, nodding flowers suit gravelly beds alongside other high-elevation perennials. It draws bumblebees and hummingbirds to cold-climate and high-altitude gardens.How to Identify
Appearance
Size & Dimensions
Height8" - 2'4"
Width/Spread8" - 1'
Reaches mature size in approximately 2 years
Bloom Information
Flowering comes in mid to late summer, roughly July to August, later than most lowland penstemons. The dusky tubular flowers open in tiers from the lower whorls upward over three to four weeks. Cool mountain nights and bright days keep the bloom going well into the short alpine season.
Detailed Descriptions
Flower Description
deep wine-purple to dusky maroon, sometimes creamFoliage Description
greenGrowing Conditions
Sun Requirements
Requires 5-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Penstemon whippleanus needs full sun to light shade and gritty, sharply drained soil that mirrors its rocky mountain home, with a neutral to slightly alkaline pH. It is very cold-hardy, suited to USDA zones 4-7, but is intolerant of heat, humidity, and wet winter soil at low elevation. Lean mineral soil and careful watering keep the crown sound, while rich or soggy ground brings rot. Plants are grown from seed sown in autumn or given a cold, moist chilling period, as the seed needs cold to germinate. Like many short-lived penstemons, it lives only a few years but self-sows where the ground stays open and gravelly. Overhead summer water and crowded, fertile beds shorten its life.Pruning
Little pruning is needed for this mountain perennial. Spent flower stalks can be cut back after bloom, leaving a few to ripen seed for self-sowing. The basal rosette is left intact through winter, since it carries the plant into the next season.Container Growing
✓ Suitable for container growing
Minimum container size: 2 gallons