Few carpeting plants provide such a splash of colour in spring as the common white form of Arabis as it tumbles over a wall or covers a bank. Unfortunately it is all too often allowed to run wild in a small rockery, where it is invasive and looks untidy when out of flower. To keep the plants in check, theshould be cut back after flowering. It is an extremely easy plant to grow, which partly accounts for its popularity.
VARIETIES: The Common White Rock Cress is A. albida (A. cau-casica) – height 9 in., spread 2 ft.
Flowering period: March-April with sporadic blooms until June. The more compact double form (Flore Pleno’) is popular – the blooms are larger but the plant is less free-flowering. White is not the only colour-you can grow the variety ‘Rosabella’ (pink) or ‘Coccinea’ (red). There is also a slow-growing variety with variegated– A. albida ‘Variegata’. Avoid A. albida if you want a low-growing compact plant – choose instead a prettier and less rambling species such as A. blepharophylla (height 3 in., spread 9 in., flower colour deep rose) or A. ferdinandi-coburgii ‘Variegata’ (height 4 in., spread 1 ft. flower colour white, remain brightly variegated all year round).
SITE AND SOIL: Any well-drained garden soil will do – thrives in sun or light shade.
PROPAGATION: Divide clumps in autumn or plantin a cold frame in late summer. Species (not named varieties) can be raised from sown under glass in spring or summer.