Cosmos bipinnatus 'Peppermint Rock'

RHS Plant Profile

cosmea 'Peppermint Rock'

RHS / Joanna Kossak

Synonyms

Cosmos 'Peppermint Rock'

Annual Biennial

An erect, half-hardy annual with finely-divided, feathery foliage. White flowers, with a pink picotee edge to the petals, are borne from summer into autumn on branched stems to 1.2m tall

Position

Full sun

Soil Types

Chalk, Clay, Loam, Sand

Max Height

1-1.5 metres

Max Spread

0.5-1 metres

Size

Time to Maturity: 1 year
Max Spread: 0.5-1 metres
Max Height: 1-1.5 metres

Growing Conditions

Chalk Clay Loam Sand

Moisture: Moist but well–drained
pH: Acid or Alkaline or Neutral

Position

Full sun

Aspect: West–facing or East–facing or South–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: Asteraceae
Native to GB/Ireland: No
Foliage: Deciduous
Habit: Columnar upright
Genus: Cosmos can be annuals or perennials with simple or pinnately divided leaves and large, long-stalked daisy-like flowers in summer
Name Status: Unresolved

How to Grow

Cultivation

Grow in moist, but well-drained soil in full sun. Suited to annual or cut-flower borders or as a summer infill

Propagation

See sowing seeds indoors

Suggested planting locations and garden types

Patio and container plants
Cottage and informal garden
Flower borders and beds
Cut flowers

Pruning

Deadhead to prolong the flowering season

Pests

May be susceptible to aphids and slugs

Diseases

May be susceptible to grey moulds