Canna 'Sémaphore'

RHS Plant Profile
canna 'Sémaphore'

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Synonyms

Canna 'Pacific Beauty'

Conservatory Greenhouse Herbaceous Perennial
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A striking, deciduous rhizomatous perennial with lush bronze to dark purple foliage. Erect stems produce bright orange-yellow flowers from mid summer to early autumn. Suitable for pots and containers

Position

Full sun

Soil Types

Loam, Sand

Max Height

0.5-1 metres

Max Spread

0.5-1 metres

Size

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

Growing Conditions

Loam Sand
Moisture
Moist but 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)
H3

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Cannaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Clump forming
Genus
Canna are rhizomatous herbaceous perennials with erect stems bearing ovate leaves, with showy flowers with showy petal-like staminodes and small, coloured petals and sepals, borne in racemes or panicles in summer and autumn
Name Status
Accepted

How to Grow

Cultivation

As a patio plant grow in pots of peat-free compost in a sheltered site in full sun. Plants can also be planted into a sunny border. Water freely and apply a high potassium feed every 2-3 weeks in the growing season. Lift the rhizomes in autumn when frost blackens the foliage. Store over winter in barely moist compost in frost-free conditions. See canna cultivation for further information

Propagation

Propagate by division of rhizomes in spring

Suggested planting locations and garden types

  • Architectural
  • City and courtyard gardens
  • Cottage and informal garden
  • Mediterranean climate plants
  • Patio and container plants
  • Conservatory and greenhouse
  • Flower borders and beds

Pruning

Leave to die back in autumn, deadhead flowers to prolong flowering

Pests

May be susceptible to caterpillars, glasshouse red spider mite and aphids

Diseases

May be susceptible to canna viruses