I've always considered the Penstemon family to be the royalty of our Western wildflowers. Their beauty and regal presence in bloom are unmatched by few other perennials. With over 300 species to choose from, there is a Penstemon (Beardtongue) for every type of planting; from rock garden to large-scale xeriscapes, there are a lot of great choices. Growing Penstemon is straightforward, as they are extremely resilient (when well matched to their planting site), and are excellent naturalizing plants when encouraged to re-seed themselves. And last but not least, Penstemon's nectar-rich flowers are indispensable to pollinators like bumblebees and hummingbirds.
Planting and Growing Penstemon Successfully
The keys to successfully growing Penstemon include:
Planting them into "lean" (infertile) fast draining non-clay soils. Sandy or gravelly soils are ideal.
Use them in new plantings where they can enjoy establishing themselves without a lot of root competition from mature neighboring plants.
Planting in full sun.
Deep, but infrequent watering (once established).
Leaving some seeds to ripen on the plants when deadheading. Seedlings from the original plants are always more vigorous and longer lived than their parents.
Mulching with gravel. This encourages re-seeding and protects the crowns from sitting wet over the winter. Bark mulch is a no-no that can induce fungal problems and rot the plants.
Growing Penstemon: Garden Care
Penstemon are pioneer plants. They are nature's choice to be among the first plants to colonize disturbed landscapes that result from fire, erosion and road cuts. These are very nutrient-efficient plants and excessive fertilization (especially with Miracle-Gro or other chemical fertilizers) pushes excessive growth and makes them much less perennial. When growing Penstemon, to keep them healthy and blooming strongly, a once-annual application of a natural/organic fertilizer in the fall with Yum Yum Mix is ideal. No compost or manure; it's too rich.
24-36" tall x 15" wide. The Richfield form of Eaton's Beardtongue was selected for its overall vigor and flower production. It blooms in early to mid-spring blooming with tall spikes of brilliant red flowers. Drought resistant/drought tolerant plant (xeric).
Penstemon heterophyllus Electric Blue is a selected form of the Foothills Beardtongue, a small growing evergreen shrub from California, that blooms in late spring with a memorable display of intensely blue flowers. .
Compactum is hands down one of the very best native wildflowers for water-wise gardens. This tiny shrub has a profusion of bright scarlet flowers in late spring and tidy, tight growing branches of evergreen pine needle-like leaves. Perfect for borders or accenting larger perennials. Drought resistant/drought tolerant plant (xeric).
Exclusive. Coconino County desert beardtongue is an incredible bloomer with numerous spikes of intensely deep pink tubular flowers in late spring. A willing re-seeder, it spreads gently, helping to fill in difficult-to-plant areas. Drought resistant/drought tolerant plant (xeric).
This is an exceptional small growing, evergreen plant that covers itself with hundreds of bright light orange, yellow throated flowers in late spring-early summer. A western native perennial, Luminous Pineleaf Beardtongue thrives in well-drained soils with plenty of sunlight. High Country Gardens 2016 Plant of the Year, 2016 Green Thumb Award Winner.
Penstemon Red Rocks (Beardtongue) is a superb hybrid variety that blooms most of the summer with large rose-pink flowers. The plants are vigorous and have attractive glossy green foliage. A 1999 Plant Select winner. Drought resistant/drought tolerant plant (xeric).
Exclusive. Blue Lips has beautiful flowers and foliage. It blooms in late spring with short spikes of blue-lipped, lavender throated flowers. Shear off the faded flowers to reveal the wonderful blue-gray evergreen foliage. Drought resistant/drought tolerant plant (xeric). A High Country Gardens introduction. 2009 Plant of the Year.
Palmer's Beardtongue blooms in early summer with tall spikes of fragrant, light pink flowers in early summer. Very xeric and heat tolerant, it is a willing reseeder for use in colonizing harsh sites. Drought resistant/drought tolerant plant (xeric).
Dark Towers Hybrid Beardtongue (Penstemon 'Dark Towers' PP 20,013) is a tall hybrid Penstemon that blooms in late spring with large, light pink flowers that are held over wine-red foliage. Well adapted to the moister growing conditions in the eastern half of the US.
As a certified "penstemaniac," I'm always looking to add new species and varieties to our High Country Gardens selection. Here are three new/returning favorites for spring.
Penstemon pinifolius - New. A little known, but outstanding species native to southwestern New Mexico and southeastern Arizona, pineleaf penstemon is my favorite of all the Beardtongues. The plants are long-lived, have fine-textured, pine needle-like evergreen foliage and bloom in late spring/early summer with a profuse display of orange-red tubular flowers. All of the pineleaf penstemons are more adaptable when it comes to soil; as long as the planting site drains quickly, they will grow well in loamy soils. With hundreds of tubular flowers, the hummingbirds love this species.
Penstemon pinifolius ' Mersea Yellow' - A returning favorite. An English cultivar, it was selected for its pure yellow flowers and has it back to the US where we can use it as an excellent choice for the xeriscape (waterwise garden) or rock garden. A tidy grower, it's a great choice for edging flowerbeds and pathways where it looks good year-round. 'Mersea Yellow' is a fabulous companion for English lavender.
Penstemon heterophyllus 'Electric Blue' - New. Known as the Foothills beardtongue, this California native is unrivaled for its intensely blue flowers. This is a species that demands Spartan growing conditions; a gravelly/sandy soil is mandatory. Placement on a slope or raised bed is ideal. Careful watering once established (after about 8-10 weeks) is also important. Don't put it on a drip system as 'Electric Blue' hates consistently moist soil. Adapted to a Mediterranean climate (rain/snow from late fall into mid-spring and almost no summer rain), it really needs very little supplement watering once it reaches the start of its second growing season and beyond. Plant it with Sundancer Daisy (Hymenoxys), Fame Flower (Phemeranthus) and cold hardy Cacti.
Penstemon pinifolius 'Compactum'' - This is an outstanding form of Pineleaf beardtongue that has a more compact growth habit and smaller mature size than is typical. It blooms in late spring with a profuse display of scarlet-red flowers.