Monday, January 23, 2012

Beardtongue - More Appealing Than It Sounds

Penstemon x mexicali 'Prairie Twilight'
The name, "Beard-tongue", doesn't sound at all appealing. Monstrous, perhaps. Or a symptom of illness. Yet, among plants, the Beard-tongue is much more appealing than it sounds. The name belongs to the genus, Penstemon (pronounced PEN-stem-on) and refers to the flowers' five stamens - 4 fertile and 1 infertile. Trumpet-shaped penstemon flowers more or less resemble open mouths. The infertile stamen, protruding through the mouth, suggests the common name. This photo by Walter Siegmund appearing at Wikipedia, shows a good example.

Penstemon flower - closeup

Or is that Mick Jagger coughing up a hairball?

Penstemon is a large genus including over 250 species. Most are native to North America. As you can see from the PLANTS Profile map, they enjoy a very wide distribution, and may be found from alpine to desert environments. In addition to the species, very many hybrids have been developed. Many of the newer ones are derived from Mexican species. Though hardiness differs by species and hybrid, they tend to share other requirements - full sun to partial shade, well-drained soil, pH between 6.1 to 7.8.

Flower spikes, rising above the foliage, generally blossom from June through September. Species range in height from 4 inches to 72 inches. As you might expect, the shorter species tend to be more cold-hardy. Foliage is usually evergreen. I recommend them for alpine gardens, rock gardens, low perennial borders, hanging baskets and and containers.

Tall penstemons are wonderful in groupings, adding height, color and texture to mixed annual and perennial borders. They're marvelous for cut flowers. All penstemons attract butterflies and hummingbirds.

Though penstemon's have enjoyed mild popularity since the 19th century, the selection of Penstemon digitalis 'Husker Red' as the 1996 Perennial Plant of the Year sent their popularity soaring. Consequently, many new varieties and hybrids have been developed.

When choosing penstemons for your perennial garden, select those which are hardy in your climate zone. The USDA climate zone map is an indispensable resource. If the ones you like are not hardy in your area, don't despair, they can be treated as annuals. If only semi-hardy, a good layer of mulch over winter may protect the crowns enough to survive.

Before planting, take a soil sample to your nearest Cooperative Extension Service office for analysis. Follow their instructions. If amendments are recommended, incorporate them into the soil when cultivating. Cultivate to a depth of 10 inches. Remember, good drainage is essential.

You might wonder whether penstemon has any known medicinal attributes. As a matter of fact, various species do. Herbal Medicine of the American Southwest, by Charles Kane, says that penstemon has been used as a poultice for skin wounds, insect bites and rashes. HerbNET reports that penstemon has also been used to relieve toothache, stomachache, chest pains, fever and chills.

In review, penstemons are wonderful for cut flowers, and for attracting hummingbirds and butterflies. They're also fine for xeriscaping. Those with medicinal herb gardens may consider including penstemon in their collections. With so many species and hybrids available, you're sure to find several that are appropriate for your garden.

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A. Joseph Marshall said...

I looked at the map where these grow and only 6 are found in Georgia. Have you seen these before around Savannah?

GoGardenNow said...

Good observation. The PLANTS database notes the following: Our county data are based primarily on the literature, herbarium specimens, and confirmed observations. However, not all populations have been documented, so some gaps in the distribution shown above may not be real. Remember that only native and naturalized populations are mapped! In other words, those counties where populations have not been confirmed may still contain some. Savannah is in Chatham County, and the PLANTs profile database does confirm native or naturalized Penstemon species there. Whether specific hybrids are growing in Chatham County, I don't know. Before purchasing plants, determine whether they are recommended for the climate zone where you live.