Penstemon 'Gentianoides' of gardens — Bushy, upright, semi-woody at the base

Overview

Penstemon 'Gentianoides' of gardens 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 'Gentianoides' of gardens grows best in full sun, and tolerates most soils and neutral to alkaline pH. Its UK hardiness is rated H3-H5.

About

Penstemon 'Gentianoides' of gardens is a perennial Penstemon in the Plantaginaceae, notable for a long flowering season from June to September. It forms a well-branched, upright plant with a semi-woody base and narrow, glossy mid to dark green leaves. Best grown in full sun on light, fertile, free-draining loam or sand. Winter wet is the common cause of losses, so choose a sheltered, south- or west-facing position where the soil is neutral to alkaline.

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 'Gentianoides' of gardens sits in the Plantaginaceae and presents as a well-branched, upright perennial with a semi-woody base and narrow, glossy foliage that is semi-evergreen to evergreen. Flowering runs June to September, giving an extended summer display from terminal stems. Position it in full sun on light, fertile, free-draining loam or sand; neutral to alkaline soils suit it best. Plant on a south- or west-facing, sheltered aspect whenever possible — exposure and drainage matter here because winter wet causes most losses. The published UK hardiness range H3–H5 translates as from borderline to fully hardy depending on site and winter severity, so give the most exposed gardens extra protection or place the plant where frost and prevailing winds are reduced. Use Penstemon 'Gentianoides' of gardens in sunny mixed borders and gravel beds where soils drain freely, or in containers positioned against a warm, sheltered wall. Its semi-evergreen foliage provides structure beyond the flowering months, and the long June to September bloom period supplies sustained summer interest for pollinators and flower displays alike.

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 'Gentianoides' of gardens 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

Care notes

Pruning and caring for Penstemon 'Gentianoides' of gardens

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 'Gentianoides' of gardens?

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 'Gentianoides' of gardens?

Penstemon 'Gentianoides' of gardens prefers full sun. It suits sheltered positions.

What soil does Penstemon 'Gentianoides' of gardens need?

Penstemon 'Gentianoides' of gardens 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 'Gentianoides' of gardens?

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 'Gentianoides' of gardens hardy in the UK?

Penstemon 'Gentianoides' of gardens 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 'Gentianoides' of gardens?

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

Browse all Penstemon →