Beardtongue 'Dark Towers'
Penstemon 'Dark Towers' · Plantaginaceae
Deep wine-red leaves that keep their colour all summer, with tall stems of pale pink, tubular flowers in early summer.
- Size
- 3 ft tall, 24 in wide
- Zones
- 3 to 8
- Light
- Full sun
- Flowers
- Early June to mid July
- Pets
- Not checked
- Job in a bed
- Drift
A bed built around beardtongue 'Dark Towers'
The planner designed this bed around beardtongue 'Dark Towers' when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why beardtongue 'Dark Towers' stands where it does.
The plants
- 1 Beardtongue 'Dark Towers' × 3, pink
- 2 Winter heath × 9, white
- 3 Coral bells 'Firefly' × 8, red
- 4 New England aster 'Alma Pötschke' × 4, pink
- 5 Silver sage × 1, silver leaves
- 6 Ornamental onion 'Purple Sensation' × 5, purple
- 7 Grecian windflower × 12, blue
Why this plant
- The only spires. The others are bells, airy sprays, daisies and others. Shape reads at a distance, where colours blur.
Why here
- Anchors a back corner. At 3 ft it is one of the taller plants here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to New England aster 'Alma Pötschke' (3½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for six weeks. From early June to mid July.
- Part of the bed's peak. With coral bells 'Firefly' and ornamental onion 'Purple Sensation' in early June: 3 kinds at once. No week has more.
Planned as a cottage garden: 25 of the 25 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. Not everything here depends on flower: silver sage earns its place with leaves. The flowers run from late January to mid October, but stop for 4 weeks from early August.
The planner's own design check: 12 Excellent, 4 Good, 1 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where beardtongue 'Dark Towers' goes in a border
At 3 ft it belongs in the middle of a bed. In the planner's ten height classes it is medium tall (2½ to 3 ft).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
An improvement on 'Husker Red': darker, taller, with pink flowers in place of white. The dark seed heads and foliage carry on after the flowers.
- Dark foliage in full sun
- Early summer spires
- Seed heads
What to plant with beardtongue 'Dark Towers'
Plants recorded as good partners for it, and what each pairing does:
- Yarrow 'Moonshine': in flower together for five weeks, from mid June.
- Prairie dropseed: takes over when it finishes, flowering from mid August; a low mound at the foot of its spires.
- Purple coneflower: in flower together for three weeks, from late June.
Questions about beardtongue 'Dark Towers'
Does beardtongue 'Dark Towers' need sun or shade?
Beardtongue 'Dark Towers' grows in full sun (6 or more hours of direct sun a day).
It wants ordinary well-drained soil, of average fertility, and little watering once settled.
What zones does beardtongue 'Dark Towers' grow in?
USDA zones 3 to 8. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does beardtongue 'Dark Towers' flower in my zone?
In zone 5 it flowers early June to mid July. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Mid June to mid July |
|---|---|
| Zone 4 | Mid June to mid July |
| Zone 5 | Early June to mid July |
| Zone 6 | Early June to mid July |
| Zone 7 | Late May to early July |
| Zone 8 | Late May to early July |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should beardtongue 'Dark Towers' be planted?
20 in (50 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 cm), so a group knits into one patch.
It grows 3 ft (90 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many beardtongue 'Dark Towers' plants do I need?
At 20 in apart, set out in staggered rows:
- 4 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 14 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as a group of three or five, with a second group further along in the other number.
In the bed above, the planner used three in one group.
Is there a native plant like beardtongue 'Dark Towers'?
Beardtongue 'Dark Towers' is not native to North America. These North American natives come closest to doing its job:
- Purple milkweed: the same job in a bed, the same size and the same flowering time; purple, not pink, bold leaves, not medium.
- Pale purple coneflower: the same job in a bed, the same flowering time and the same colour; 4 in narrower, wants dry soil.
- Ohio spiderwort: the same job in a bed and the same flowering time; 4 in narrower, blue, not pink.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
What flowers after beardtongue 'Dark Towers'?
Beardtongue 'Dark Towers' is over by mid July. These start as it finishes and carry the same spot on, so it never goes flat:
- Black-eyed Susan: from mid July to mid September, 24 in tall, to stand in front of it and cover its fading stems.
- Bee balm: from early July to early August, 3 ft tall.
- Lilyturf: from early August to mid September, 16 in tall, to stand in front of it and cover its fading stems.
What does beardtongue 'Dark Towers' look like in winter?
Beardtongue 'Dark Towers' holds some of its leaves into winter, more in a mild year or a sheltered spot, and they look tired by March. Cut the old ones off as new growth starts.
More Penstemon
- Beardtongue 'Husker Red' Penstemon digitalis 'Husker Red'
- Beardtongue 'Prairie Dusk' Penstemon 'Prairie Dusk'
- Firecracker penstemon Penstemon eatonii
- Foxglove beardtongue Penstemon digitalis
- Hairy beardtongue Penstemon hirsutus
- Large beardtongue Penstemon grandiflorus
- Pineleaf penstemon Penstemon pinifolius
- Rocky Mountain penstemon Penstemon strictus
In these guides
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8
Every fact on record
- Type
- Perennial
- Size
- 3 ft (90 cm) tall, 24 in (60 cm) wide
- Plant
- 20 in (50 cm) apart
- Height class
- Medium tall (2½ to 3 ft)
- Place in the bed
- Middle
- Flowers
- Early June to mid July; upright spires; pink
- Leaves
- Medium texture, semi-evergreen; burgundy, purple
- Shape
- Upright, clumping
- Hardy in
- USDA zones 3 to 8
- Light
- Full sun
- Soil
- Average, well-drained
- Water
- Low
- Feeding
- None needed
- Family
- Plantaginaceae
Not yet checked against an outside reference: its figures rest on general horticultural knowledge. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.