Penstemon rupicola 'Diamond Lake'

RHS Plant Profile
penstemon 'Diamond Lake'

Save a plant

Where do you want to save Penstemon rupicola 'Diamond Lake'?

Plants I own
Wishlist
Go to My Plants
penstemon 'Diamond Lake' RHS 1999
Plants for pollinators
Herbaceous Perennial

'Diamond Lake' is a prostrate evergreen sub-shrub with rounded blue-green leaves and narrowly bell-shaped pink flowers 3.5cm long in late spring and early summer

Position

Full sun, Partial shade

Soil Types

Chalk, Loam, Sand

Max Height

Up to 10 cm

Max Spread

0.1-0.5 metres

Size

Time to Maturity
2–5 years
Max Spread
0.1-0.5 metres
Max Height
Up to 10 cm

Growing Conditions

Chalk Loam Sand
Moisture
Well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun Partial shade
Aspect
West–facing or South–facing or East–facing
Exposure
Exposed or Sheltered
Hardiness

Hardiness Ratings

All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets

  • H1A: under glass all year (>15C)
  • H1B: can be grown outside in the summer (10 - 15)
  • H1C: can be grown outside in the summer (5 - 10)
  • H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
  • H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
  • H4: hardy through most of the UK (-10 to -5)
  • H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
  • H6: hardy in all of UK and northern Europe (-20 to -15)
  • H7: hardy in the severest European continental climates (< -20)
H5

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Plantaginaceae
Native to GB/Ireland
No
Foliage
Evergreen
Habit
Bushy
Genus
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
Name Status
Accepted

How to Grow

Cultivation

Grow in poor to moderately fertile, very gritty, well-drained soil in full sun. In cold areas, protect plant overwinter with a dry winter mulch. See penstemon cultivation for further advice

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

  • City and courtyard gardens
  • Coastal
  • Rock garden
  • Cottage and informal garden
  • Gravel garden
  • Patio and container plants
  • Wildlife gardens
  • Flower borders and beds

Pruning

Deadhead after flowering to maintain vigour

Pests

May be susceptible to slugs, snails and chrysanthemum eelworms

Diseases

May be susceptible to downy mildews