Aubrieta plants are far more common in Europe than in North America. In fact, the genus name derives from Claude Aubriet, a European landscape artist from the 17th century. However, this cheerful ground cover is a great candidate for edging your paths or tucking into stone walls if you meet some basic growing requirements. When the profuse magenta flowers have faded, the grayish-green foliage maintains a handsome mat that covers bare areas under leggy roses or between paving stones on a garden path.
- Botanical Name: Aubrieta spp.
- Common Name: Aubrieta; false rockcress
- Plant Type: Perennial
- Mature Size: Four to six inches
- Sun Exposure: Partial to full sun
- Soil Type: Lean, rocky
- Soil pH: Slightly acidic to alkaline; 6.5-7.5
- Bloom Time: April, May
- Flower Color: Pink, purple, white
- Hardiness Zones: USDA growing zones 4-9
- Native Area: Southwestern Europe
Caring for Aubrieta
Gardeners looking for that perfect pocket plant should consider the spring-blooming aubrieta. Plants have a very small footprint, and can establish a deep root system in the soil behind a retaining wall, while foliage and flowers can spread up to 18 inches or more wide, giving the appearance of a living wall. Aubrieta plants also provide good erosion control on hillsides, and attract butterflies with their prolific spring flowers.
Aubrieta plants shine in full sun, but will also grow in partial sun. For best results, grow plants where they will receive at least a half day of sun. Plants that grow in too much shade will lose their compact, mounded appearance, will take on a leggy look, and will have sparse flowers.
Aubrietas like a rocky, alkaline soil, which mimics the soil found in their native alpine habitats. If the pH is low, increase it with the addition of lime. Good drainage is important to prevent root rot. Use gravel, vermiculite, or another non-organic soil amendment that will help drainage without lowering soil pH.
Aubrieta plants need a moderate amount of water, but at the same time they don't like wet feet. Rocky soils that prevent standing water will keep healthy root systems on your aubrieta plants.
Temperature and Humidity
Aubrieta plants grow best in areas with cool summers that mirror their alpine climate. Periods of high humidity are fine; in fact, the cool, damp climate of Great Britain or Washington state are where you are most likely to find extraordinary specimens of aubrieta plants.
Aubrieta plants grow in lean soil, and need no supplemental fertilizer to make beautiful blooms. An occasional watering with compost tea is, at most, all the feeding aubrieta plants need.
Potting and Repotting
Pot up your aubrieta plants with a lightweight all purpose potting soil. A potting mix meant for cacti is also appropriate for aubrieta plants. Take care not to bury the foliage when potting up aubrieta. There are a few inches of brown stem beneath the foliage, and this is the working area of the plant when repotting. Lift the foliage, and carefully mound soil around the stems and roots to secure the plant in its place.
You can divide aubrieta in early fall to increase your stock. Dig the plant, and tease the clump apart with your hands or a garden fork. Replant the divisions 12 inches apart.
Varieties of Aubrieta
The most commonly seen aubrieta in gardens features bright violet flowers, like the 'Rokey's Purple' variety. However, gardeners can create a different look with the variegated 'Doctor Mules Variegated' aubrieta or the all white 'Snowdrift' cultivar. Variegated types may revert to green, so prune away any all-green stems that form.
Toxicity of Aubrieta
Aubrieta has no known toxicity to animals or people.
Aubrieta can get a bit scraggly after blooming. Keep it tidy by trimming plants back after flowering. Use shears, and trim no more than half the plant's growth at any one time.
Being Grown in Containers
Aubrieta complements the container garden as a trailing plant, softening container edges. Plant it as a companion to other rock garden flowers with similar growing needs, like dianthus.
Growing From Seeds
Sow aubrieta seeds on top of sterile potting mix. The seeds need light for germination, so press seeds down but don't cover them. Keep seeds moist at about 68 degrees F. Germination will occur in two to three weeks.
Aubrieta is rarely bothered by insect pests. Plants growing in damp, shady areas may experience downy mildew. Prevent this fungal disease by providing enough light and spacing for air circulation.
Aubrieta vs. Creeping Phlox
The flowers and form of aubrieta and creeping phlox (Phlox subulata) are so similar as to be indistinguishable at first glance. Both plants grow as a creeping mat, spreading across the border's edge or trailing down walls. However, creeping phlox plants are more heat and drought tolerant than aubrieta, which may account for its preference in American gardens.