How to Prune rock penstemon?
Deadhead after flowering to maintain vigour. Then cut back to base in early spring

rock penstemon · Penstemon rupicola
Also known as: cliff beardtongue
Grow in poor to moderately fertile, very gritty, well-drained soil in full sun. The plant illustrated here is the cultivar 'Diamond Lake'
Deadhead after flowering to maintain vigour. Then cut back to base in early spring