under 5 cm
well drained, gritty
acid - neutral - alkaline
sensitive to winter wet, grows best in gritty soil on a steep slope
Penstemon is a genus in the family Plantaginaceae. It is a large genus native to N-America. They are usually low growing herbaceous plants or sub-shrubs with irregularly shaped flowers. They prefer full sun and many are well suited to rock gardens.
Seed - sown in September - November
Seed not covered and stored outside until germination.
Mat forming alpine plant. Sensitive to winter wet. Needs very sharp drainage, preferably on a steep slope.