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Rock cress

Rock cress has white flowers and crisp green leaves.

Rock cress is a ground cover for small areas.  It works well in rock gardens, along retaining walls and as an edging plant. 

This plant has some cultivated varieties. Go to list of cultivars.

 

Botanical name:

Arabis caucasica

All Common Names:

Rock cress, wall rock cress, garden rock cress

Family (English):

Mustard

Family (Botanic):

Brassicaceae (formerly Cruciferae)

Tree or Plant Type:

  • Ground cover,
  • Perennial

Native Locale:

  • Non-native

Landscape Uses:

  • Foundation,
  • Massing,
  • Patio/sidewalk

Size Range:

  • Small plant (6-12 inches)

Light Exposure:

  • Full sun (6 hrs direct light daily)

Hardiness Zones:

  • Zone 4,
  • Zone 5 (Chicago),
  • Zone 6,
  • Zone 7

Soil Preference:

  • Acid soil,
  • Alkaline soil,
  • Moist, well-drained soil

Tolerances:

  • Dry sites,
  • Occasional drought,
  • Alkaline soil

Season of Interest:

  • Early spring

Flower Color & Fragrance:

  • Fragrant,
  • White

Shape or Form:

  • Creeping

Growth Rate:

  • Moderate

More Information:

Size and Method of spreading

Rock cress grows 6 to 12 inches high.  It is a trailing-rooting ground cover. 

Trailing-rooting ground covers have trailing stems that spread out from a central root system.  These stems spread out horizontally over the ground and can root where they come in contact with the soil.  New shoots will be formed at the point where rooting occurs.

Plant Care

Rock cress need full sun and a well-drained soil.  Soil can be slightly acidic to alkaline  This plant is drought tolerant and wet soils must be avoided.  After flowering, shearing the plants will encourage them to remain neat and compact.

Disease, pests, and problems

Root and crown rot can be a problem in wet soils.
Aphids and fungal leaf spots are occasional problems.

Disease, pest, and problem resistance

Resistant to deer.

Native geographic location and habitat

Native to the Mediterranean.

Leaf description

The leaves that grow from the base of the plant are obovate and tend to lie flat.  The leaves on the stems are borne alternately and are lobed.  All the leaves have some whitish hairs.

Flower description

The white flowers are produced in early spring in loose clusters.  Each flower has 4 petals and this is typical of the mustard family.  The flowers are fragrant.

Fruit description

Fruit are thin, pod-like silicles; not ornamentally important.

Cultivars and their differences

Snow Cap rock cress  (Arabis caucasica 'Snow Cap'):  Flowers more heavily than the species.

Location of Arabis caucasica (Rock cress) at the Arboretum

We do not seem to have this in our living collection.