Penstemon: Tubular Joy in the Garden

What better rhythm in a garden than the coming and going of penstemons.

Penstemon pinifolius
Item # 75760 		Penstemon pinifolius
Pineleaf Penstemon

each $5.29
3 to 6 $4.99
7 or more $4.79
Penstemon x mexicali 'Red Rocks' ™
Item # 75796 		Penstemon 'Red Rocks' ™
Red Rocks™ Hybrid Beardtongue

each $5.29
3 to 6 $4.99
7 or more $4.79

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What better rhythm in a garden than the coming and going of penstemons. In her book Passionate Gardening author Lauren Springer likens the succession of flowering penstemons to a symphony of color. By choosing specimens and planting wisely you can achieve an array of continual color through several seasons. Some species reach heights of 28-inches; most average 16-inches and others prefer ground level at 4-inches.

Penstemons are also called “beardtongues” because of a fifth enlarged stamen within the tubular flower. Some say it resembles a tongue. There are nearly 300 species of penstemons. Though most are suited to the West and Great Plains, they can also be grown in higher rainfall regions if special treatment is applied.

Planting and Cultural Considerations

Because many Penstemon are adapted to grow in harsh Western habitats, it is important to keep a few cultural considerations in mind when bringing them into your garden.

  • Plant only in well-drained soils.
  • Avoid overly enriched soils; too much compost can shorten life spans.
  • Plant high, leaving the top of the root ball just above the surrounding soil.
  • Keep plants from crowding one another.
  • Avoid bark, grass clippings or compost mulches; water retentive mulch materials cause disease, especially in wet, cold weather. Leave them un-mulched or use gravel.
  • Deadheading (removal of spent flower spikes) lengthens a plant’s bloom production for that season.

Penstemons in More Humid Climates

The key factor in growing Penstemons is to have well-drained soil. Create a raised bed of sand. They don’t like rich loam or clay. If possible plant them on a sunny slope where they can dry out quickly. Mulch with gravel or chicken grit.

Penstemons that are native to the Midwestern, Eastern and Southeastern states are listed in “Growing Penstemons: Species, Cultivars, and Hybrids,” a publication of the American Penstemon Society compiled by Dale Lindgren and Ellen Wilde (Ellen lives in Santa Fe). It is a wonderful reference book about everything a ‘Penstemaniac’ needs to know.

Penstemon tubaeflorus is a good choice for the more humid states as it occurs as a native plant in states ranging from Connecticut to Florida to Illinois. Penstemons that do well in most parts of the United States include P. strictus, p. pinifolius, and P. barbatus “Elfin Pink.” You may need to experiment a bit to find a variety that works for you. Try planting in several locations and see where they do best.

New to Penstemons?

If you’ve never grown penstemons and live within zones 5-9, do give our Penstemon Sampler a try. The starter kit comes with six favorites:

  • P. strictus,
  • P. pinifolius,
  • P. pinifolius ‘Mersae Yellow’,
  • P. x mexicali ‘Red Rocks’,
  • P. cardinalis and
  • P. barbatus ‘Elfin Pink.’

Penstemon Hints

  • Allow to Re-seed Penstemon will sometimes live for only 2 or 3 years. To keep them going, allow some of the plants to set seed, so don’t deadhead them, which means cutting off the spent flowers. The volunteer seedlings will be more vigorous and longer lived than the original parent plant.
  • Fertilize Sparingly Because penstemon prefer lean conditions, it’s necessary to fertilize once each year. In the fall apply a light application of an organic or natural fertilizer. Yum Yum Mix is an excellent fertilizer for Penstemon and other native plants. It has a high trace mineral and phosphorus content while being low in nitrogen.
  • Loosen the soil and add organic nutrients at planting time. Mix a handful of Yum Yum Mix into the soil of the planting hole. Then water the Beardtongue transplants with Superthrive and Liquid Seaweed (Root Stimulator Combination Pack) to get them off to a good start. (Nursery grown plants benefit from extra nutrition when making the move from cultivation into the wild.)

Penstemons for Higher Elevations

If you live at around 7,500 feet, the following penstemons do well at that altitude.

  • Penstemon virens Blue Mist Beardtongue will thrill all who grow it with its floriferous spikes of lavender-blue flowers that bloom in late spring and early summer. A small growing, compact plant it is well suited to exposed windy spots. A good re-seeder when happy in its environment. Zones 4-9.
  • Penstemon linarioides v. coloradensis Colorado Narrowleaf Beardtongue is a superb Colorado native with thin, blue evergreen leaves and clouds of lavender-blue flowers in late spring. Zones 4-9.
  • Penstemon procumbens ‘Claude Barr’ Mat Penstemon is vigorous and ground-hugging with rounded, glossy, dark green foliage and small, deep blue, trumpet-shaped flowers. Excellent in rock gardens. True to its mountain origins, this plant is not recommended for the hot, dry southwestern U.S. Zones 4-8.
  • Penstemon pinifolius and cultivars Pineleaf Beardtongue is a fabulous species from the mountains of New Mexico. It’s numerous cultivars are long lived and bloom in shades of orange, scarlet and yellow. Looks good when out of bloom because of its evergreen needle like foliage. Zones 4-9.

Lauren Springer says fiery red penstemons add exclamation points to the garden. But all of the penstemons bring a true vibrancy to any landscape. The added bonus is butterflies, bees and humming birds can’t get enough of the penstemons.