Polemonium archibaldiae

RHS Plant Profile
towering Jacob's ladder

Synonyms

Polemonium foliosissimum misapplied

Award of Garden Merit
Herbaceous Perennial

A bushy, clump-forming perennial to around 1m high, with long, pinnate leaves, divided into up to 30 lance-shaped leaflets held in offset pairs. Bell-shaped flowers, usually violet-blue but sometimes white, are produced in loose clusters on upright stems, from late spring through to late summer or early autumn. White-flowered varieties are often scented

Position

Full sun, Partial shade

Soil Types

Chalk, Clay, Loam, Sand

Max Height

0.5-1 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity
2–5 years
Max Spread
0.1-0.5 metres
Max Height
0.5-1 metres

Growing Conditions

Chalk Clay Loam Sand
Moisture
Moist but well–drained or Well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun Partial shade
Aspect
East–facing or South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H5

Colour & Scent

Fragrance Flower
Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Polemoniaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Bushy
Genus
Polemonium can be annuals or herbaceous perennials or upright or spreading habit, with pinnate leaves and usually clustered, tubular, bell, or funnel-shaped flowers
Name Status
Correct

How to Grow

Cultivation

Grow in fertile, moist but well-drained soil, will benefit from some shade where summers are hot

Propagation

Propagate by seed, sown in containers in a cold frame in autumn or spring, or by division in spring

Suggested planting locations and garden types

  • Cottage and informal garden
  • Gravel garden
  • Wildflower meadow
  • Banks and slopes
  • Flower borders and beds

Pruning

Deadhead regularly to encourage new flowers

Pests

Generally pest-free

Diseases

May be susceptible to powdery mildews