Description Rocky Mountain Penstemon produces a rosette of deep green leaves and multiple flower stalks up to 60 cm high bearing intense purple-blue 2.5 cm wide flowers. Plants bloom in early summer and self-sows very easily. This introduced perennial prefers dry soil locations in open spruce or pine forests. It can naturalize in these areas however soil that remains wet for extended periods can lead to plant mortality during the winter. A good plant for attracting butterflies and hummingbirds. It is often grown for use as a cut flower. Perennial hardy to Zone 4. For many native and perennial plants, late fall is the best time to sow seed directly outside. Why you ask? Simply put, many of these plants produce seed that is viable but dormant. This means allowing seeds to naturally stratify over winter will “wake up” the dormant seed for best results. How to Grow 1050 seed/gram. Sow seed indoors in a soil-less medium at the beginning of March. Keep at 15° C for the 20 to 30 day germination period. After that, grow on under lights at the same temperature before hardening off and transplanting outside to a sunny site with sandy open soil after the danger of frost has passed. Seed can also be directly sown in its preferred location in late October. This allows any dormant seed to be naturally stratified during the winter.
