Grown mainly for its neat, low growing, mat-forming foliage. The dainty flowers are a welcome site but they may not be as abundant as they are with many other alpines.
Family: Brassicaceae (cabbage)
Botanical Name: Arabis (alpina)
Common Names: spreading rock cress, mountain rock cress, white rock cress.
Foliage: Simple small leaves. Green or variegated. Evergreen.
Flowers: Errect racemes of small white, pink or purple flowers.
Flowering Period: Spring to early summer.
Soil: Moist but well-drained soil (chalk, clay, sand or loam). Any pH.
Conditions: Best in full sun. Any aspect, in either an exposed or sheltered location.
Habit: Mat forming, low growing.
Type: Annuals or evergreen perennials.
Hardiness: Fully hardy in all areas of the UK (-15 to -20°C).
Good for hot dry conditions, also poor and infertile soils. Suitable for rock and gravel gardens, wall crevices, alpine troughs, pots and containers .
Trim faded flowers to maintain compactness.
Susceptible to attack by aphids and gall midge. Can be affected by downy mildew and white blister.
Propagate by softwood cuttings.
A. caucasica (syn. A. albida) a common white arabis with grey-green foliage and a show of white flowers in spring. Good named forms include:
A. c 'Plena' (syn. Arabis alpina 'Flore Pleno') has rough green leaves and double, white flowers in late spring. Height to 8in (20cm), spread to 24in (60cm).
A. c 'Rosabella' has pink flowers. Height to 6in (15cm).
A. c 'Snowcap' a compact version with abundant pure white flowers in spring. Height to 4in (10cm), spread to 20in (50cm). Available at Thompson and Morgan.
A. c 'Pixie Cream' has creamy white flowers. Height: 4in (10cm), spread: 10in (25cm). Available at Thompson and Morgan.
A. procurrens 'Variegata (syn. jerdinandi-coburgii 'Variegata') forms a low growing carpet of attractive cream and green variegated foliage, giving interest throughout the year. Available at Thompson and Morgan.