Aubrieta (False Rock Cress) Plant Profile

An Excellent Flowering Ground Cover

Aubrieta - False Rockcress

Ellen Rooney / Getty Images 

Aubrieta, a cheerful ground cover, is a great candidate for edging your paths or tucking into stone walls if your site meets 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. These plants are far more common in Europe than in North America. The genus name derives from Claude Aubriet, a European landscape artist from the 17th century.

Botanical Name Aubrieta spp.
Common Name Aubrieta, false rock cress
Plant Type Herbaceous perennial
Mature Size 4 to 6 inches tall; 12-to 24-inch spread 
Sun Exposure Full sun to part shade
Soil Type Lean, rocky soil
Soil pH 6.5 to 7.5 (slightly acidic to alkaline) 
Bloom Time April, May
Flower Color Pink, purple, white
Hardiness Zones  4 to 9 (USDA)
Native Area Rocky regions of southwestern Europe
Aubrieta growing in rock wall
Martin Stankewitz/Getty Images 
Aubrieta and Yellow Leopard's Bane
Michael Davis/Getty Images 
Aubrieta in flower on rockery
 Photos Lamontagne/Getty Images

How to Grow Aubrieta

Aubrieta thrives best when planted in well-draining, alkaline soil in a full sun location. In midsummer, the foliage tends to die back and will benefit from a hard shearing. As a member of the mustard family, this is a tough plant that requires little care. Once established, it has a good tolerance for drought, and it resists nibbling by deer.

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.

Light

Aubrieta plants shine in full sun, but will also grow in part shade. 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, take on a leggy look, and have sparse flowers.

Soil

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.

Water

Aubrieta plants need a moderate amount of water, but 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 is where you are most likely to find extraordinary specimens of aubrieta plants.

Fertilizer

Aubrietas grow in lean soil and need no supplemental fertilizer to make beautiful blooms. At most, occasional watering with compost tea is all the feeding aubrieta plants need.

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.

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.

Pruning

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.

Propagating Aubrieta

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.

Growing From Seeds

Aubrieta can be hard to find as nursery plants, so it is often grown from seed. 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 Fahrenheit. Germination will occur in two to three weeks.

Varieties of Aubrieta

  • 'Rokey's Purple' is among the most commonly seen aubrieta in gardens; it features bright violet flowers.
  • 'Doctor Mules Variegated' aubrieta offers a completely different look; it's important to know, however, that variegated types may revert to green, so prune away any all-green stems that form.
  • 'Snowdrift' is a popular all-white cultivar.
Aubrieta 'Snowdrift'
Snowdrift Aubrieta. Charlotte Bleijenberg/Getty Images
Aubrieta 'Doctor Mules Variegated'
Doctor Mules Variegated Aubrieta. Gratysanna/Getty Images 

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.

Creeping Phlox
Creeping Phlox. MaYcaL/Getty Images

Landscape Uses

Spring-blooming aubrieta makes a perfect pocket plant for garden walls and rock gardens. The 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, giving the appearance of a living wall. Aubrieta plants also provide good erosion control on hillsides and attract butterflies with their prolific spring flowers.