As of 2010, there are 20 known species belonging to the plant genus Cistus, all of which are perennial shrubs. These plants hail from the Canary Islands and countries that border the Mediterranean. They have bright five-petaled flowers in shades of white and purple. In some species, the petals have a dark red spot at the base. These flowering plants are commonly called rockrose.
The flowers of the rockrose measure 4 inches (10 cm) across and have yellow stamens in the center. These plants flower between the months of May and June. The plants in the Cistus genus originated from rocky areas, which is why they prefer well drained, even stony, soil and bright sunlight. They tolerate a wide pH range in soil and water, although soils that are too chalky will produce yellowish leaves.
Apart from being garden flowers, the plants in this genus are also an important raw material used by perfume companies. Labdanum, a commercially extracted gum, is used to produce perfume and comes from Cistus ladanifer. As of 2010, the gum is very valuable to the perfume industry due to its resemblance to ambergris, a substance that is banned in many countries.
To propagate the Cistus plant, one should take greenwood plant cuttings during the summer months or root softwood during the winter months. It is recommended that it be planted during the later parts of spring through summer like other Mediterranean shrubs, and not during the autumn season. When planting the cuttings, it is important to handle the root ball gently. One should remember not to tease the roots out from the root ball because they are very brittle.
For ideal growth, the plant should be deadheaded during the blooming period. Deadheading will also improve the plant’s overall appearance during the bloom period. Once the blooming period is over, the shrubs should be pinched back in order to stimulate a bushier growth in preparation for the winter months in colder climates.
Although plants in the Cistus genus are not harmed by frost and the cold, it is better for the plants if they have a sheltered position, as cold winds can damage the delicate flowers. To encourage growth and flowering, one should trim the Cistus shrub after the flowering season, but not overly prune it. The plants do not have a long lifespan and need replacement every few years. A typical lifespan for Cistus species is from eight to 10 years, while its hybrids can last as long as 15 years.