Digitalis vs. Penstemon


By Cassy Aoyagi:  Looking for something that will catch every eye? The spectacular variety of tubular, bell-shaped flowers make Foxgloves a focal point in many gardens.  As usual, however, there is an equally charming, bright and beautiful water-wise alternative.


Digitalis (Foxglove)

Foxglove, AKA Digitalis, is native to parts of Europe, Africa and Asia. While Foxgloves carry all the gaity and romance of a favorite childhood fairytale, they have a dark side.  Foxglove:

  • Leaves focal point space barren when it’s done blooming.  When Digitalis
  • stops blooming, it gives out completely. Its stalks must be cut to the ground.  The foliage often withers into our desert soils. At best, the flowers leave behind desiccated clumps of foliage that rarely bloom again.
  • Places poison close to home.  While compounds in Digitalis can be therapeutic – it is included in medicines that support a failing heart – it is a beautiful, appetizing toxin for those in good health.
  • Becomes invasive.  Digitalis pushes its seeds into wild lands and out-competing native species that support native wildlife and natural beneficial insects that keep those we consider pests at bay.

American Penstemon

formla_032The “dry” alternative to Digitalis is incredibly charming.  In fact, its fans have formed the American Penstemon Society to promote the incredibly large North American genus!  Its many handsome attributes include:

  • Having strength in numbers.  More than 50 species are native to California alone.  They range from coastal to desert to lower alpine plant communities. Because their habitat range is so broad, it is possible to find a Penstemon for almost any kind of soil, from rock to meadow-like gardens.
  • Providing unmatched color, variety, foliage.  A Penstemon garden would provide enough color, height variety and texture changes to stand alone with out any other plants! Many varieties that thrive in Southern California range from 12″ to 4′ tall, and effervesce florescent blue, lilac, red, pink, white and purple flowers.
  • Maintaining its form and foliage past its bloom.  While Penstemon is not blooming, most varieties maintain clean, green foliage year round. (Some placed in more extreme climates will enter into a mild dormancy period.)
  • Requiring little work.  To promote new flowers and extend bloom periods, a little dead heading is recommended.  Penstemmon is realatively pest-free.
  • If you are planning to plant a big dry one somewhere – consider giving it some friends.  Penstemon thrives in amongst other natives and low water plants.  Some of the best companion plants are Blue-eyed Grasses, Yarrows, Deer Grass and Artemisias, all of which love sun like Penstemon and provide magnificent background for Penstemon’s pops of color.

For more guidance on where to plant big dry ones, see our past Wet-to-Dry Exchange articles.