The rock rose (Helianthemum vulgar) is an evergreen perennial flowering shrub, native to southern Europe. Rock rose produces somewhat flat flowers in the summer, in shades of white, yellow, pink and red. Their ability to thrive in poor soil and their attraction to butterflies make rock rose a favorite in the home landscape. Rock rose is hardy to USDA Zones 5 through 8.
Grow the rock rose in full sun in the warmest part of the garden. If the soil in the planting area does not drain well, incorporate a 3-inch layer of sand into the soil and mix it in well.
Allow the soil to completely dry prior to watering. Water until the soil is saturated.
Fertilize the rock rose once a year, in the spring. Use a liquid, 10-10-10 formula according to the rate suggested on the package. Water immediately after applying fertilizer.
Deadhead the rock rose by pinching off dead flowers during the blooming season. This will encourage the plant to further bloom.
Pinch the tips of the rock rose plant when it has finished blooming. This will stimulate the rock rose plant to grow bushier. Stop pinching the plant in September and resume when the plant begins actively growing in the following spring.
Protect the rock rose in USDA Zone 5 winters by inserting pine boughs into the soil around them and allowing the branches to hang over the rock rose.