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Penstemon Care, Growing the Beardtongue Flower

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Penstemon Care, Growing the Beardtongue Flower

Penstemon, or beardtongue flower, is low maintenance and drought tolerant.

Photo © Matt Lavin
Have you never heard of the flowering penstemon? Don’t tell that to the American Penstemon Society. Yes, there is an organization dedicated to cultivating, propagating, and identifying species of this hardy native perennial. Or, perhaps the two men charged with felony theft in an attempt to steal 600 pounds of Palmer’s penstemon seedpods from Utah’s Zion National Park could tell you more about the value of this little plant. These men may regret exchanging their freedom for several bags of seed worth $25,000, but you won’t regret growing the beardtongue flower in your landscape.

Latin Name:

Family Plantaginaceae, Genus Penstemon

Common Names:

Beardtongue

Zone:

3-9, although some varieties may only be hardy to zones 4 or 5

Size:

Most penstemons are one to three feet tall, but the Palmer’s penstemon can grow up to six feet.

Exposure:

Full sun

Bloom Period:

Early to midsummer

Description:

Penstemon plants are herbaceous perennials that feature lance shaped foliage and spikes of tubular flowers. Flower colors are pink, red, white, purple, or rarely yellow. The nickname of bearded tongue refers to the pollen-free stamen that protrudes from the flower, resembling a bearded iris in this aspect. Botanists often refer to the appearance of this beard when distinguishing among penstemon species.

Planting:

Penstemons are easy to start from seed, which is just as well, as many of the species are short-lived perennials. Seeds may germinate better after a period of aging, mimicking their conditions in the wild, so you can store seed for several years before planting. If you sow the seeds in the garden, do so in autumn, to allow a natural stratification period. Alternatively, you can stratify the seeds in the refrigerator for three months if you plan to start them indoors. If you purchase penstemon seeds, be sure to check the growing zone, as tender varieties like the ‘Tubular Bells’ series are often sold alongside the hardy perennial types.

Penstemons don’t compete well with other plants, so give them plenty of space in the garden. Plant penstemons in the spring, and choose a site with full sun and very well draining soil. These plants are prairie natives, and prefer rocky or sandy lean soil types over rich garden loam. It’s OK to amend the soil with compost to achieve proper tilth, but avoid manure applications.

Maintenance:

Keep the penstemon flowerbed weeded regularly. A three-inch layer of organic mulch can help to control weeds, and rock mulch is also a suitable choice. Penstemons tolerate drought, but one inch of water per week in the summer will keep plants vigorous and promote better blooming. You can cut the spent flower stems back after blooming to help plants look tidy.

Design Tips:

  • Penstemon plants look best in groups of at least three to five plants.
  • Include the smaller varieties of penstemon in the rock garden.
  • Penstemon flowers are a valuable source of nectar for bees, butterflies, and hummingbirds in the wildflower garden.
  • Plant tall penstemon types in the middle or back of the sunny mixed perennial border.
  • Penstemon flowers make good cut flowers, although most people don’t think them as bouquet candidates.
  • Browsing deer avoid penstemon plants.

Varieties:

  • Dark Towers: Similar to Husker Red, but with pale pink flowers and darker foliage.
  • Elfin Pink: Topping out just shy of 12 inches, a good rock garden plant.
  • Husker Red: Perhaps the most well known variety, due to being named perennial plant of the year in 1996. Plants feature reddish-purple foliage and white flowers.
  • Jingle Bells: Reddish orange flowers are a beacon to hummingbirds.
  • Piña Colada series: Blue, rose, or white flowers on compact plants.
  • Red Riding Hood: Monrovia’s successful introduction has red flowers and an upright growth habit.

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