Overview
Penstemon gloxinioides 'Southgate Gem' 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 gloxinioides 'Southgate Gem' grows best in full sun, and tolerates most soils and neutral to alkaline pH. Its UK hardiness is rated H3-H5.
About
Penstemon gloxinioides 'Southgate Gem' is a perennial in the Plantaginaceae with a multi-stemmed, upright habit and a semi-woody base. It carries narrow, glossy mid to dark green leaves that remain semi-evergreen to evergreen in milder sites. Flowering runs from June to September, producing the tubular penstemon blooms characteristic of the genus. It suits sunny, sheltered positions with freely draining soil.
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 gloxinioides 'Southgate Gem' sits within the Plantaginaceae and grows as a perennial with an upright, multi-stemmed habit and a semi-woody base. The foliage is narrow and glossy, often holding on through winter in milder areas, and the plant flowers from June to September. Plant in a south- or west-facing, sheltered spot with full sun and a light, fertile, free-draining loam or sandy soil. Aim for neutral to alkaline conditions; avoid winter waterlogging, as prolonged wet in winter causes most losses. It is rated H3–H5 (borderline to hardy), so in colder or exposed locations give extra winter protection or situate it against a warm wall. Where space and drainage permit, place 'Southgate Gem' in sunny borders, raised beds or gravelly, well-drained mixes where it will receive shelter from prevailing winds. Allow summer flowering to run through June to September, which provides a sustained display across the warmer months.
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 gloxinioides 'Southgate Gem' 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 gloxinioides 'Southgate Gem'
- 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 gloxinioides 'Southgate Gem'?
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 gloxinioides 'Southgate Gem'?
Penstemon gloxinioides 'Southgate Gem' prefers full sun. It suits sheltered positions.
What soil does Penstemon gloxinioides 'Southgate Gem' need?
Penstemon gloxinioides 'Southgate Gem' 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 gloxinioides 'Southgate Gem'?
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 gloxinioides 'Southgate Gem' hardy in the UK?
Penstemon gloxinioides 'Southgate Gem' 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 gloxinioides 'Southgate Gem'?
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
