Overview
Penstemon strictus is a bushy, upright, semi-woody at the base perennial in the genus Penstemon, part of the Plantaginaceae family, with semi-evergreen or evergreen; narrow, glossy, mid to dark green foliage. Penstemon strictus grows best in full sun, and tolerates most soils and neutral to alkaline pH. Its UK hardiness is rated H3-H5. Suggested uses include rock gardens, borders, xeriscaping and pollinator gardens. It is native to United States.
About
Penstemon strictus is a perennial in the Plantaginaceae with upright, well-branched stems and a semi-woody base. It bears narrow, glossy mid to dark green leaves and may remain semi-evergreen. Plant in full sun on light, fertile, free-draining loam or sand with a neutral to alkaline pH. Avoid winter waterlogging, as winter wet causes most losses.
Wikipedia contributors, CC BY-SA 4.0 — Penstemon strictus
About the genus
Penstemon, the beardtongues, is a large genus of roughly 280 species of flowering plants native to North America from northern Canada to Central America. It is the largest genus of flowering plants endemic to North America. As well as being the scientific name, penstemon is also widely used as a common name for all Penstemon species alongside beardtongues.
Wikipedia contributors, "Penstemon", CC BY-SA 4.0 — Penstemon
In the garden
Penstemon strictus is a perennial native to the United States that produces upright, well-branched stems from a branched crown. The foliage is narrow and glossy, often remaining semi-evergreen through milder winters, while the plant is valued for its summer display and use in pollinator planting. Give Penstemon strictus a sunny, sheltered position—south or west facing—on light, fertile, free-draining loam or sand. It prefers neutral to alkaline soil; persistent winter moisture is the main cause of failure, so siting where water drains away is essential. Hardiness is rated H3–H5, which corresponds to borderline to hardy in UK terms, so it will need the better-drained, sheltered spots in colder districts and will be more straightforward in milder locations. In the garden it suits rock gardens, gravel borders, xeriscaping schemes and pollinator areas where summer flowering is wanted. Regular pruning of spent stems after flowering and avoiding heavy winter mulch against the crown will help reduce rot; expect a reliable summer display from June to September when it provides accessible nectar for bees and other insects.
Growing conditions
Best soil and position for Penstemon
- Sunlight
- Full sun
- Soil type
- Light, fertile, free-draining loam or sand
- Soil pH
- Neutral to alkaline
- Soil moisture
- Well drained; winter wet causes most losses
- Aspect
- South or west facing
- Exposure
- Sheltered
- UK hardiness
- H3-H5
Plant details
Penstemon strictus size, habit and characteristics
- Plant type
- Perennial
- Habit
- Bushy, upright, semi-woody at the base
- Foliage
- Semi-evergreen or evergreen; narrow, glossy, mid to dark green
- Suggested uses
- Rock gardens, borders, xeriscaping, pollinator gardens
- Native to
- United States
Care notes
Pruning and caring for Penstemon strictus
- Cultivation
- Drainage and shelter decide whether a penstemon is perennial or annual in your garden. Plant in spring rather than autumn so the roots establish before winter, and leave the top growth standing until spring as crown protection. Regular deadheading is what sustains the extraordinarily long season. Given the modest hardiness of most cultivars, taking cuttings every summer is sensible insurance.
- Pruning
- Leave stems intact over winter, then cut back to low healthy buds in mid-spring once frosts have passed. Deadhead continuously through summer, cutting spent spikes to a side shoot.
- Propagation
- Semi-ripe cuttings taken in late summer root quickly and are the standard method - and the usual replacement for winter losses. Species can be raised from seed.
- Pest resistance
- Slugs take young spring shoots; capsid bug and eelworm occur but are uncommon.
- Disease resistance
- Powdery mildew and leaf spot appear on crowded plants. Root rot follows winter waterlogging.
Frequently asked questions
How do I grow Penstemon strictus?
Drainage and shelter decide whether a penstemon is perennial or annual in your garden. Plant in spring rather than autumn so the roots establish before winter, and leave the top growth standing until spring as crown protection. Regular deadheading is what sustains the extraordinarily long season. Given the modest hardiness of most cultivars, taking cuttings every summer is sensible insurance.
Where is the best place to plant Penstemon strictus?
Penstemon strictus prefers full sun. It suits sheltered positions.
What soil does Penstemon strictus need?
Penstemon strictus is adaptable and grows happily in most soil types, including light, fertile and free-draining loam or sand. It prefers neutral to alkaline soil. Aim for soil that stays well drained; winter wet causes most losses.
How do I prune Penstemon strictus?
Leave stems intact over winter, then cut back to low healthy buds in mid-spring once frosts have passed. Deadhead continuously through summer, cutting spent spikes to a side shoot.
Is Penstemon strictus hardy in the UK?
Penstemon strictus has an RHS hardiness rating of H3, meaning it is half-hardy, tolerating -5 to 1°C, and may need winter protection in colder areas.
How do I propagate Penstemon strictus?
Semi-ripe cuttings taken in late summer root quickly and are the standard method - and the usual replacement for winter losses. Species can be raised from seed.
More in the Penstemon genus
- Penstemon 'Raven'Beardtongues
- Penstemon campanulatusbellflower beardtongue
- Penstemon campanulatus 'Andenken an Hahn'Penstemon
- Penstemon campanulatus 'Evelyn'Beardtongue
- Penstemon campanulatus 'Garnet'Penstemon
- Penstemon campanulatus 'Hidcote Pink'Beardtongue
- Penstemon campanulatus 'Pink Endurance'Beardtongue
- Penstemon cyananthusBlue Penstemon
