Helianthemum nummularium

RHS Plant Profile

common rockrose

RHS

Other common names

flower of the sun, cor-rosyn cyffredin

Synonyms

Helianthemum nummularium 'Rock Mixed'
Helianthemum chamaecistus
Helianthemum vulgare
Cistus helianthemum

Alpine Rockery Shrubs

Buy this from Plant Nurseries
10 Suppliers

A low, spreading evergreen shrub to 15cm tall, with tiny, oval grey-green leaves, and saucer-shaped, sulphur yellow flowers to 2.5cm across, produced over a long period from late spring to summer

Position

Full sun

Soil Types

Chalk, Clay, Loam, Sand

Max Height

0.1-0.5 metres

Max Spread

0.1-0.5 metres

Size

Time to Maturity: 5–10 years
Max Spread: 0.1-0.5 metres
Max Height: 0.1-0.5 metres

Growing Conditions

Chalk Clay Loam Sand

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

Position

Full sun

Aspect: South–facing or East–facing or West–facing
Exposure: Exposed or 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: Cistaceae
Native to GB/Ireland: Yes
Foliage: Evergreen
Habit: Matforming
Genus: Helianthemum are bushy or spreading evergreen shrubs with small paired leaves and saucer-shaped flowers borne in short racemes in spring and early summer
Name Status: Correct
Plant Range: Europe, SW Asia

How to Grow

Cultivation

Prefers alkaline to neutral, moist but well-drained soil in full sun, but will tolerate acid soil and dry conditions. Survives well amongst short grass. This plant was included in the RHS Helianthemum (rock rose) trial 2024-2026 https://www.rhs.org.uk/plants/trials-awards/ongoing-plant-trials/helianthemum

Propagation

Propagate by seed sown in autumn, or take softwood cuttings in late spring or early summer

Suggested planting locations and garden types

Gravel garden
Rock garden
Wildlife gardens
Banks and slopes

Pruning

Pruning group 10 after flowering

Pests

Generally pest-free

Diseases

May be susceptible to honey fungus in gardens where it is present but insufficient data to determine degree of susceptibility