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Penstemon 'Sour Grapes' M. Fish AGM

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© RHS 1999

Characteristics

Plant type

Herbaceous Perennial

Habit

Clump-forming

Resilience

Hardiness

H4 (hardy - average winter)

Colour

Flower

Blue, Purple and White in Summer

Foliage

Green in Autumn, Spring, Summer and Winter

Size

Ultimate height

0.5-1 metres

Ultimate spread

0.1-0.5 metres

Time to ultimate height

2-5 years


Preferred common name

penstemon 'Sour Grapes'

Family

Plantaginaceae


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

'Sour Grapes' is an erect perennial to 60cm in height, with lance-shaped leaves and dense panicles of tubular, two-lipped flowers blending purple and blue shades, whitish within the throat

Synonym(s)

  • Penstemon 'True Sour Grapes'

How to grow

Sunlight

  • Full sun
  • Part shade

Aspect

  • South-facing, East-facing or West-facing
  • Exposed or Sheltered

Cultivation

Grow in fertile, well-drained soil in full sun or partial shade. In cold areas, protect plant overwinter with dry winter mulch

Soil

  • Well-drained
  • Acid, Alkaline or Neutral
  • Sand, Loam or Chalk

Propagation

Propagate by softwood cuttings in early summer or semi-hardwood cuttings in midsummer. Propagate by division in spring

Suggested planting locations and garden types

Cottage/Informal Garden or Flower borders and beds


How to care

Pruning

Deadhead after flowering to maintain vigour. Then cut back to base in early spring

Pests

May be attacked by slugs, snails, glasshouse red spider mite, and leaf and bud eelworms

Diseases

Generally disease free