Cistus albidus - White-leaved rock rose

Growing Cistus albidus from seed requires careful preparation to break the natural dormancy of its seeds and ensure good germination.

The most reliable method involves mechanical scarification followed by soaking. To begin, it is essential to weaken the hard shell of the seeds, which prevents water absorption and delays germination. This scarification can be done by lightly rubbing the seeds with sandpaper or making a delicate incision on their coating. Once this step is completed, the seeds should be soaked in room-temperature water for 12 to 24 hours, which further softens their shell and hydrates the embryo.

Once the seeds are prepared, sow in spring, when daytime temperatures are around 15 to 20°C. Use a well-draining substrate, composed of a mix of light compost and coarse sand, to avoid excess moisture, which is harmful to young seedlings. Place the seeds on the surface and cover them with a very thin layer of substrate, as they require some light to germinate properly. Keep the soil slightly moist but never waterlogged, and place the sowing in a warm, sunny spot. Germination may take several weeks, depending on environmental conditions.

When the young seedlings reach 3 to 5 cm in height and develop their first true leaves, they can be transplanted into individual pots to encourage root development. Continue using a well-drained substrate and avoid overwatering, as Cistus albidus is a Mediterranean plant adapted to dry soils. Once the young plants are strong enough (usually after 3 to 4 months), they can be gradually acclimatised outdoors before being planted permanently in the ground the following autumn or spring.

Since young plants are sensitive to frost, it is best to grow them in pots under shelter during their first winter, especially in regions with harsh winters. Once well-established in the ground, they will become hardy bushes, capable of withstanding temperatures as low as -12, or even -15°C in very well-drained soil.