Penstemon 'Rock'

From 2000 to 7000 feet of elevation, rocky slopes, limestone crevices and bluffs, and seemingly soilless cracks in limestone ledges provide the required sharp drainage for Baccharis-leaf penstemon in the Edwards Plateau and Trans-Pecos of Texas and south into Mexico. This densely branched subshrub with herbaceous growth above becomes woody at its base. It may be erect or somewhat sprawling. It's 1- to 2-inch-long, thick, smooth, or fuzzy leaves show small teeth along the margin. Inch-long straight tubular scarlet flowers open along the stalk from spring through summer.

Baccharis-leaf penstemon makes a desirable rock garden plant with excellent drainage and roots shaded with mulch or rocks from the late afternoon sun. It may die to the ground in winter or need to be strongly cut back to promote a bushy habit.