Common rock rose
Helianthemum nummularium · Cistaceae
📷 Wikimedia Commons · CC BY-SA 2.5
The gardener's calendar
In autumn, ease off feeding and take the chance to clean up around common rock rose and prepare for winter.
ID card
- Family
- Cistaceae
- Plant type
- Spreading sub-shrub
- Foliage
- Evergreen
- Flowering
- May to July
- Adult height
- 30 to 40 cm
- Hardiness
- Good (down to around -15°C)
- Origin
- Mediterranean regions and Southern Europe
- Growth
- Moderate
✓ Taxonomy verifiedSource: AI estimate · hardiness: reliability high.
Expert tips
The key tip
Helianthemum nummularium dreads stagnant moisture more than drought. Plant it in very well-drained, even poor soil: add gravel or sand when planting.
The common mistake
Most people water it like other perennials: it then rots at the roots, the base blackens, and it disappears in a wet winter.
The pro's trick
In a humid oceanic or mountain climate, plant it on a rocky mound or in a raised container.
Care
Sun exposure
Yellow helianthemum demands a sunny location (6 to 8 hours of direct sunlight minimum) for generous and vigorous flowering. In partially shaded situations, flowering becomes sparse and the plant stretches. Avoid locations exposed to strong winds.
Watering
This plant appreciates well-drained and dry soil. Water moderately after planting, then let nature take its course once established. Excessive watering promotes root rot. Even during prolonged drought, helianthemum resists well.
Soil
Prefer poor to average, well-drained, chalky or neutral soil. Helianthemum thrives in rocky or sandy substrate and tolerates heavy, wet soils very poorly. Adding sand or gravel at planting time improves drainage.
Pruning
After flowering (July-August), perform light pruning to maintain a compact shape and encourage dense branching. Cut back stems by a third of their length. Avoid cutting into old wood; the plant regrows poorly from old wood.
Fertilizer
No fertilizer application is necessary. Helianthemum prefers poor soils and responds poorly to excess fertility, which reduces flowering and promotes excessively lax growth.
Diseases and pests
This plant is relatively insensitive to pests and diseases in ideal conditions (perfect drainage, sun). In overly wet soil, grey mold can appear. Good drainage prevents most problems. No specific treatment is generally needed.
Did you know?
Helianthemum is a true sun lover: its Greek name "Helianthemum" literally means "flower of the sun." Its small bright yellow flowers open only in the presence of direct light and close at sunset, a fascinating strategy for conserving water in arid climates. Traditionally, this robust plant was highly prized in rock gardens and Mediterranean slopes for its extreme hardiness and virtually maintenance-free nature.
Where to buy it
Best planted in autumn so the roots settle in before summer, or in early spring once the frost has passed. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, October, November.
Add this plant to my garden →Plants from the same family
- Grey cistusCistus albidus
- Salvia cistusCistus salviifolius
- Montpellier rockroseCistus monspeliensis
- Laurel-leaved cistusCistus laurifolius
- Curly rockroseCistus crispus
- Cretan rock roseCistus creticus
Tips generated and checked by Viridia — adapt them to your local climate.