Celosia argentea (Spicata Group) 'Spiky Purple'

RHS Plant Profile

cockscomb 'Spiky Purple'

Annual Biennial

'Spiky Purple' is a bushy annual with a slightly more unusual appearance than other argentea varieties in that it has clusters of purple flower heads rather than individual spikes. These appear from summer until early autumn

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

0.1-0.5 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 1 year
Max Spread: 0.1-0.5 metres
Max Height: 0.1-0.5 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): H2

Colour & Scent

Season	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family: Amaranthaceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Bushy
Genus: Celosia can be annuals, perennials or shrubs, with simple or lobed, alternate leaves and tiny, brightly coloured flowers in large, plume-like inflorescences. Many garden selections are closely related to C. argentea
Name Status: Unresolved

How to Grow

Cultivation

Annual that can be grown outside once frosts have passed. Grow in peat-free, loam-based potting compost in full light with good ventilation. Outdoors, plant in moist but well-drained fertile soil in full sun in a sheltered position. Apply a balanced liquid fertiliser every two weeks

Propagation

Propagate by seed

Suggested planting locations and garden types

Patio and container plants
Flower borders and beds

Pruning

No pruning required

Pests

Glasshouse red spider mite, glasshouse whitefly and aphids may be a problem under glass

Diseases

Foot and root rot and fungal leaf spot diseases may occur