Agapanthus 'Kalmthout Blue'

RHS Plant Profile
African lily 'Kalmthout Blue'

Save a plant

Where do you want to save Agapanthus 'Kalmthout Blue'?

Plants I own
Wishlist
Go to My Plants
Herbaceous Perennial
Buy this from Plant Nurseries
1 Suppliers

A deciduous, clump-forming herbaceous perennial with strap-shaped mid-green leaves and sturdy stems which produce panicles of trumpet-shaped flowers in the summer. These are mid blue in bud, opening to a paler blue flower

Position

Full sun

Soil Types

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

Position

Full sun
Aspect
South–facing or West–facing
Exposure
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
Amaryllidaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Clump forming
Potentially harmful
Humans/Pets (dogs, cats): harmful if eaten. Wear gloves and other protective equipment when handling. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus
Agapanthus are clump-forming perennials with narrowly strap-shaped leaves, evergreen in some species, and erect stems bearing umbels of funnel-shaped blue or white flowers
Name Status
Accepted

How to Grow

Cultivation

Grow in fertile, moist but well-drained soil in full sun. In cold areas mulch in winter. In containers, grow in a peat-free, loam-based compost. May need winter protection. See agapanthus cultivation

Propagation

Sow seed when ripe or in spring, keep in cold frame whilst small and protect in winter. Divide clumps in Spring every two-three years

Suggested planting locations and garden types

  • City and courtyard gardens
  • Cottage and informal garden
  • Patio and container plants
  • Flower borders and beds

Pruning

Cut back in autumn as foliage goes brown. Cut back flower spikes as they go over, unless you want to keep seedheads for winter interest

Pests

May be susceptible to slugs and snails and agapanthus gall midge

Diseases

May be susceptible to a virus