Growing Penstemon: Garden Care
Penstemon are pioneer plants. They are nature's choice to be among the first plants to colonize disturbed landscapes that result from fire, erosion, and road cuts. These are very nutrient-efficient plants and excessive fertilization (especially with Miracle-Gro or other chemical fertilizers) pushes excessive growth and makes them much less perennial. When growing Penstemon, to keep them healthy and blooming strongly, a once-annual application of a natural/organic fertilizer in the fall with Yum Yum Mix is ideal. No compost or manure; it's too rich.