Plant Profile: Penstemon

June is the month of flowers, with favorites like roses, irises and peonies in bloom. But one of my favorite June flowers is Penstemon, sometimes referred to as beardtongue because of the fuzzy growths inside the plants bloom.

dark towers penstemon

Dark Towers penstemon is a popular cultivar. (Photo courtesy of Terra Nova Nursery)

Penstemon is a group of plants that includes more than 250 species and most of them are native to areas of North America from the southern states up through Canada. They are considered one of the most attractive (to humans, at least) of the wildflowers. Because they are comfortable in northern climates, penstemon grow very well in our northern gardens. Many are hardy to USDA Zone 3 (northern Minnesota) and they are easy to grow. You can grow them easily from seed, too.

Large beardtongue (Penstemon grandiflorus) is native to Minnesota, growing in the prairie and lakes areas from the Twin Cities all the way up to Grand Forks. This plant is about 3 feet tall with large pinkish purple tubular shaped blooms. Each plant will have up to 6 blooms arranged around the stem. It grows well in sandy soil and full sun.

Husker red penstemon

Penstemon will bloom in a variety of light, but hails from sunny prairies.

More commonly seen in gardens is foxglove beardtongue (Penstemon digitalis), which is native as far north as Iowa and is found all over Minnesota, though it is not native here. Foxglove beardtongue typically has white flowers and is an adaptable plant, growing in a variety of sun situations. It is very attractive to pollinators, especially mason and bumblebees as well as hummingbirds. Whenever mine are in bloom, the bumblebees are all over it, flying in and out of the tubular flowers.

Foxglove beardtongue has also been the subject of some breeding efforts. ‘Husker Red’ is perhaps the most used cultivar in home gardens. With its reddish stems, purple toned leaves and abundant pink-to-white flowers, it’s a contrast plant in beds and borders. Blooms can last up to three weeks and this plant looks great planted in masses. An even more dramatic cultivar is ‘Dark Towers,’ which has deep maroon leaves and blooms that lean more toward reddish pink than white. Both cultivars grow about 3 feet tall and don’t spread too much.

Plant penstemon where the foliage and flowers will stand out, in the middle of the border. They look especially at home with other prairie plants, such as coneflower, grasses and perennial sunflowers.


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