Penstemon cobaea
prairie beard-tongue
A clump-forming perennial to 60cm in height, with large green oval leaves and erect spires of large, impressive, pale to deep purple, bell-shaped flowers; blooms from spring into early summer
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Size
Ultimate height
0.5–1 metresTime to ultimate height
2–5 yearsUltimate spread
0.5–1 metresGrowing conditions
Moisture
Well–drained, Moist but well–drainedpH
Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Purple | Green | ||
|---|---|---|---|---|
| Summer | Purple | Green | ||
| Autumn | Green | |||
| Winter |
Position
- Full sun
Aspect
West–facing or South–facing
Exposure
Exposed or Sheltered Hardiness
H6Botanical details
- Family
- Plantaginaceae
- Native to GB / Ireland
- No
- Foliage
- Deciduous
- Habit
- Clump forming
- Genus
Penstemon may be deciduous or evergreen perennials or subshrubs, with simple, narrow leaves and racemes or panicles of bell-shaped or funnel-shaped flowers in summer and early autumn
- Name status
Correct
How to grow
Cultivation
Grow in fertile, moist but well-drained soil in full sun or partial shade. In cold areas, protect plant overwinter with a dry winter mulch. See penstemon cultivation for further advice
Propagation
Propagate by softwood cuttings in early summer or semi-ripe cuttings in midsummer
Suggested planting locations and garden types
- City and courtyard gardens
- Cottage and informal garden
- Gravel garden
- Patio and container plants
- Rock garden
- Prairie planting
- Wildflower meadow
- Wildlife gardens
- Flower borders and beds
Pruning
Remove spent flower spikes to help encourage a long season; cut all stems down to low-growing shoots in mid- to late March
Pests
May be susceptible to aphids, slugs, snails and chrysanthemum eelworm
Diseases
May be susceptible to Powdery mildews
Get involved
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