Overview
Helianthemum nummularium is a matforming alpine rockery in the genus Helianthemum, part of the Cistaceae family, with evergreen foliage. It typically grows around 0.1-0.5 metres tall and 0.1-0.5 metres wide, reaching full size in around 5-10 years. Helianthemum nummularium grows best in full sun, and tolerates most soils and any pH. Its UK hardiness is rated H5. It is attractive to pollinators. Suggested uses include gravel garden, rock garden and wildlife gardens. It is native to Europe and SW Asia.
About
Helianthemum nummularium is a compact, low-growing evergreen shrub that reaches a height of up to 15 cm. It features small, oval leaves that are a grey-green hue. The plant produces wide, saucer-like flowers in a soft yellow shade, measuring up to 2.5 cm in diameter. These blooms appear in abundance from late spring through summer, providing a lengthy display.
About the genus
Helianthemum consists of evergreen shrubs that can be bushy or spread out. They feature small, paired leaves and produce saucer-shaped flowers that appear in short racemes during the spring and early summer.
Growing conditions
Best soil and position for Helianthemum
- Sunlight
- Full sun
- Soil type
- Chalk, Clay, Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained, Well-drained
- Aspect
- South-facing, East-facing, West-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H5
Plant details
Helianthemum nummularium size, habit and characteristics
- Plant type
- Alpine Rockery, Shrubs
- Habit
- Matforming
- Foliage
- Evergreen
- Height
- 0.1-0.5 metres
- Spread
- 0.1-0.5 metres
- Time to full height
- 5-10 years
- Suggested uses
- Gravel garden, Rock garden, Wildlife gardens
- Native to
- Europe, SW Asia
Care notes
Pruning and caring for Helianthemum nummularium
- 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
- Pruning
- Pruning group 10 after flowering
- Propagation
- Propagate by seed sown in autumn, or take softwood cuttings in late spring or early summer
- Pest resistance
- Generally pest-free
- Disease resistance
- May be susceptible to honey fungus in gardens where it is present but insufficient data to determine degree of susceptibility
Frequently asked questions
How do I grow Helianthemum nummularium?
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.
Where is the best place to plant Helianthemum nummularium?
Helianthemum nummularium prefers full sun. It suits exposed and sheltered positions.
What soil does Helianthemum nummularium need?
Helianthemum nummularium is adaptable and grows happily in most soil types, including chalk, clay, loam and sand. It is happy in soil of any pH. Aim for soil that stays moist but well-drained to well-drained.
How do I prune Helianthemum nummularium?
Pruning group 10 after flowering.
How big does Helianthemum nummularium grow?
Helianthemum nummularium reaches a height of 0.1-0.5 metres and a spread of 0.1-0.5 metres. It takes around 5-10 years to reach full size.
Is Helianthemum nummularium hardy in the UK?
Helianthemum nummularium has a UK hardiness rating of H5.
How do I propagate Helianthemum nummularium?
Propagate by seed sown in autumn, or take softwood cuttings in late spring or early summer.
Is Helianthemum nummularium good for pollinators?
Yes — Helianthemum nummularium attracts and supports pollinators such as bees and other beneficial insects.