Arabis caucasica
Rock cress
Common names: Caucasian rock cress, Mountain rock cress
At a glance
- Light
- Full sun
- Pot size
- from 3 l
- Lifespan
- Perennial
- Flowering
- Mar–May
- Hardiness
- Hardy
Photo: H. Zell · CC BY-SA 3.0 · Source
Description
The rock cress (botanically Arabis caucasica) is a low, evergreen cushion plant from the Caucasus that thrives in rock gardens and on wall crowns. From March to May it develops a dense white flower carpet, providing early-season forage for bees and bumblebees. Its gray‑green, slightly fibrous leaves remain on the shoots even in winter, adding structure when the bed is otherwise quiet. It grows contentedly on lean, well‑drained soils and spreads loosely in a creeping manner without crowding other plants.
Care instructions
Plant rock cress in a sunny to full‑sun position on well‑drained, rather lean soil; heavy, clayey soil is poorly tolerated. A spacing of 20 to 30 cm is sufficient, as the plant will close into a dense cushion over time. After flowering in June, prune to about half the height to keep the growth compact and encourage a second, weaker flowering in late summer. Water only during persistent dryness and avoid additional fertilisation; excess nutrients make the cushion loose and less winter‑hardy. In a pot or on a wall crown it tolerates frost well and requires no winter protection.
The care notes were machine-translated from German.
Garden year
FloweringMar–May
Soil & site
Soil pH
Soil type
well-drained, lime-loving, lean, dry
The garden arabis likes it lean and free-draining, preferably in a sunny rock garden or wall bed. It tolerates heavy, waterlogged soils poorly, as the roots then easily rot. A chalky, rather poor soil comes closest to its natural site in rocky and scree zones. A little sand or grit mixed in improves drainage further.
Feeding
Light feeder
As an undemanding cushion perennial, the garden arabis needs practically no feeding. Soil that is too rich in nutrients makes it grow soft and prone to disease instead of flowering compactly. In spring, a thin layer of mature compost around the plant is enough; nothing more is needed.
Overwintering
The garden arabis is hardy and survives German winters outdoors without problems. What matters is a free-draining site, so that no wet collects around the roots in winter. After hard frost the foliage may look a little tousled, but it reliably sprouts fresh again in spring. Cutting back after flowering keeps the cushions compact and rejuvenates growth for the coming season.
Propagation
Methods
- From seed
- Cuttings
- Division
Sowing succeeds from spring directly outdoors or in seed trays at room temperature; the seeds are light germinators and are only pressed down lightly. After flowering in May you can also take soft cuttings from non-flowering shoots and root them in sandy compost. Older cushions that go bare in the middle are best divided in spring or early autumn, and the pieces are replanted straight away. All three ways are uncomplicated and also suit garden beginners.
Companion planting
Good neighbors
legume family (Fabaceae)
particularly well establishedLeguminous plants collect nitrogen in the soil, from which Brassicaceae benefit as heavy feeders.
For example PeaBush beanPole beanBroad beanSnow peaWrinkled pea and 36 more species in the catalogue
Source: classic companion planting (DACH-Gartenpraxis)
carrot family (Apiaceae)
You can pair celery and dill with all Brassicaceae because they repel the cabbage whitefly with their scent, a proven companion.
For example CarrotCeleriacDillParsleyFlorence fennelCoriander and 21 more species in the catalogue
Source: Bio-Gärtnerei Mixed-culture Practice
mint family (Lamiaceae)
You will notice that the intense scent of basil, thyme, and others confuses the cabbage whitefly and keeps it away from the cabbage family.
For example LavenderThymeBasilRosemarySageHyssop and 43 more species in the catalogue
Source: bio-gardening intercropping practice
nasturtium family (Tropaeolaceae)
Nasturtium serves as a trap plant for you. Aphids and cabbage whiteflies prefer it over the brassicaceae next to it.
For example NasturtiumMashua
Source: Trap plant practice in organic horticulture
Companion planting is partly traditional gardening lore. Where the reason is known, it is given.
Some of these explanations were machine-translated.
For your garden
Grow Rock cress yourself
Gartenkern tells you when frost is coming, when to sow and when to harvest, for your location.
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