Aubrieta (Aubrieta deltoidia), also called purple rock cress, is a low-growing perennial used as an edging plant or a ground cover. It produces delicate purple or blue flowers that last from three to four weeks. The plants bloom once in the spring and offer a repeat performance in the late summer. Aubrieta does best in full or part sun and rich, well-drained soil. You can sow the seeds directly into the garden in the late autumn or early spring and will sprout two to three weeks after planting.
Remove all grass, weeds and rocks from the planting area. Loosen the soil to a depth of 30 cm (12 inches) using a garden fork.
Sow the seeds liberally on top of the soil. Add enough water to moisten the soil well, but use care when watering to avoid covering the seeds too deeply.
Continue to add water whenever the surface of the soil feels dry. Once the seedlings emerge, water at ground level to avoid damaging the delicate foliage.
Prune aubretia back by half after the first blooming cycle is complete.
Remove spent flowers after the summer blooming cycle to prevent the plants from seeding and invading other areas of the garden.
Feed with a balanced fertiliser each spring, right before new growth appears.
Aubrieta can also be started indoors, approximately seven weeks before the last frost in spring. Aubrieta can also be propagated from cuttings.