Overview

Penstemon gracilis is a clump forming herbaceous perennial in the genus Penstemon, part of the Plantaginaceae family, with evergreen, semi-evergreen foliage. Penstemon gracilis grows best in full sun, and tolerates most soils and any pH. Its UK hardiness is rated H4. Suggested uses include cottage and informal garden, city and courtyard gardens, coastal, gravel garden, patio and container plants, wildlife gardens and flower borders and beds.

About

Penstemon gracilis, more commonly the slender penstemon or lilac penstemon, is flowering plant in the veronica family. It primarily grows in the northern Great Plains of the United States and southern Canada. In the wild it grows across North America, Alberta, British Columbia, Colorado, Illinois and other regions. Grow it in full sun and most soil types. In UK gardens it is hardy through an average UK winter (RHS H4). It works well for cottage and informal garden, city and courtyard gardens, coastal, gravel garden, patio and container plants, wildlife gardens and flower borders and beds. It tolerates soil of any pH, well-drained conditions and south-facing, west-facing and east-facing aspects. Plant in well-drained soil in sun or part shade.

Wikipedia contributors, CC BY-SA 4.0Penstemon gracilis

Growing conditions

Best soil and position for Penstemon

Sunlight
Full sun
Soil type
Loam, Chalk, Sand
Soil pH
Acid, Alkaline, Neutral
Soil moisture
Well-drained
Aspect
South-facing, West-facing, East-facing
Exposure
Exposed, Sheltered
UK hardiness
H4

Plant details

Penstemon gracilis size, habit and characteristics

Plant type
Herbaceous Perennial
Habit
Clump forming
Foliage
Evergreen, Semi-evergreen
Suggested uses
Cottage and informal garden, City and courtyard gardens, Coastal, Gravel garden, Patio and container plants, Wildlife gardens, Flower borders and beds

Care notes

Pruning and caring for Penstemon gracilis

Propagation
Softwood cuttings in early summer, Semi-ripe cuttings in midsummer, Division in spring
Pest resistance
Slugs, Snails, Glasshouse red spider mite, Leaf and bud eelworms
Disease resistance
Powdery mildew, Rust, Leaf spots, Southern blight

Frequently asked questions

Where is the best place to plant Penstemon gracilis?

Penstemon gracilis prefers full sun. It suits exposed and sheltered positions.

What soil does Penstemon gracilis need?

Penstemon gracilis is adaptable and grows happily in most soil types, including loam, chalk and sand. It is happy in soil of any pH. Aim for soil that stays well-drained.

Is Penstemon gracilis hardy in the UK?

Penstemon gracilis has an RHS hardiness rating of H4, meaning it is hardy through an average UK winter, tolerating -10 to -5°C.

How do I propagate Penstemon gracilis?

Softwood cuttings in early summer, Semi-ripe cuttings in midsummer, Division in spring.

More in the Penstemon genus

Browse all Penstemon