Aubretia
Also known as
Aubrieta, Purple rock cress, False rock cress, Rainbow rock cress
Keep this plantās care guide close at hand.
Get the appAbout Aubretia
Aubrieta deltoidea is a low, mat-forming evergreen perennial prized for spilling color over rock walls and edging spring borders. Native to rocky, calcareous slopes of southeastern Europe and western Asia, it forms dense cushions of small, gray-green, slightly hairy, deltoid (triangular) leaves. In mid to late spring, masses of four-petaled flowers in shades of violet, magenta, or rosy purple blanket the foliage, often with a tiny pale eye. Plants typically grow 4ā6 inches (10ā15 cm) tall and can spread 12ā24 inches (30ā60 cm), rooting lightly at the edges. Excellent drainage is essential; Aubrieta thrives in poor to moderately fertile, gritty soils that are neutral to alkaline. After flowering, a hard shear keeps the cushion compact and may encourage a light rebloom. Attractive to bees and other early pollinators, itās ideal for rock gardens, crevice plantings, and as a groundcover where heat and humidity are not extreme.
Taxonomy
Properties & Requirements
How to care for Aubretia
Water
Water newly planted Aubrieta deeply once or twice weekly for the first 4ā6 weeks, allowing the top inch of soil to dry between waterings. Once established, it is moderately drought-tolerant and typically needs water only during prolonged dry spells. Always prioritize drainage; never let the crown sit in sodden soil, especially in winter. In containers, water when the top 1ā2 inches feel dry, then allow excess to drain freely. Morning watering helps foliage dry quickly and reduces disease risk.
Light
Provide full sun (6+ hours daily) for the heaviest bloom and tightest cushions. In hot-summer climates, light afternoon shade helps prevent heat stress while maintaining floral display. Excess shade leads to open, leggy growth and sparse flowering. Plant on south to east exposures for early spring warmth, or in bright crevices where light reaches the sides as well as the top. Indoors is not suitable; Aubrieta is best grown outdoors in high light.
Nutrients
Aubrieta is a light feeder and flowers best in lean, well-drained, alkaline to neutral soils. Overfeedingāespecially high nitrogenāpromotes leafy growth at the expense of bloom. In-ground, mix in a little garden lime if soil is acidic and top-dress with a thin layer of compost or grit in early spring. For containers, apply a low-nitrogen, bloom-leaning fertilizer at half strength every 3ā4 weeks during spring flowering only. Do not fertilize in summer or winter.
Temperature
Best performance occurs in cool to mild climates. Hardy to roughly USDA Zones 4ā8, it tolerates severe frost when soils drain well. Ideal growth is between 40ā70Ā°F (4ā21Ā°C). Prolonged heat and warm, humid nights can reduce vigor; in hotter regions (Zones 8ā9), provide afternoon shade and excellent air flow. Winter wet is more damaging than coldākeep crowns elevated or in gritty media. Avoid reflected heat from south-facing walls in very warm climates.
