Paul’s Plant Pick: Penstemon ‘Dark Towers’

This week’s beautiful, but dark, star in the garden.

Last Friday, as I walked through the gardens I was joined by a number of American Goldfinches darting about, a song sparrow singing its beautiful morning song and two yellow tiger swallowtails silently following me down the path. It seemed a crime to go indoors so I used the opportunity to take another turn through the garden in search of my biweekly plant pick. At this point in the season, it is no easy task to select just one plant as there are so many budding up and bursting into bloom.

For the past two seasons I have been admiring a relatively recent perennial introduction to the TBG gardens. Penstemon ‘Dark Towers’, commonly known as Beardtongue was added to our collections last spring. I recall first hearing about the virtues of this new cultivar a few years back at a new plant forum that takes place every year at the Perennial Plant Symposium. This year’s symposium takes place July 21 through 27 in Vancouver, BC. Read more about this great gathering of passionate plant lovers and excellent networking opportunity below.

Personally, I would consider Penstemon ‘Dark Towers’ an improvement over another great garden plant, Penstemon ‘Husker Red’.  P. ‘Dark Towers’ is the product of the breeding work of Dale Lindgren of the University of Nebraska. It is a dramatic specimen in the perennial border with beautiful narrow dark burgundy foliage that provides both eye catching colour and contrast in the garden throughout the season. The best colouring is achieved when the plant is grown in full sun. Burgundy flowering stems growing to 3 ft (36”) in height yield an abundance of soft pink tubular flowers that are much loved by both butterflies and hummingbirds.

This perennial, hardy to zone three, will bloom from late spring into summer. Deadheading will encourage additional flowering. Pictures of this plant don’t do it justice. See and experience for yourself.  P. ‘Dark Towers’ is currently in bloom in the Entry Garden Walk.

While in the Entry Garden Walk, be sure to take a short walk east along the path and look up. The green roof on the straw bale shed is also looking fantastic (with species Penstemon and Coreopsis in flower). If you walk through two large pyramidal English oaks you will come to the Woodland Walk and Bird Habitat where native Penstemon digitalis is in it’s full glory. This native has begun to self seed throughout the gardens so do not be surprised to find some volunteers blooming in unexpected places (that is where mother nature and a few birds chose to plant some seeds).

Perennial Plant Symposium
It is almost time for the Perennial Plant Symposium! This yearly conference brings together breeders, growers, retailers, designers, garden writers, educators, gardeners and students from the horticultural industry for a week of informative lectures, a trade show, wonderful tours and the most incredible networking opportunity.  The symposium takes place in a different city every year. In a few short weeks, this dedicated and enthusiastic group from around the world will gather in Vancouver, British Columbia for the 31st Perennial Plant Symposium, July 21 through 27.

For more information, click on,  The symposium and incredible networking opportunity have been invaluable to my continued growth in the industry. There are many parts of this year’s symposium that I am looking forward to, however one of the things I am most excited about is the opportunity to go hiking in Whistler with world renowned plant explorer Dan Hinkly. I can hardly wait!