Repotting guide

When & how to repot Caucasian Rock Cress (Arabis caucasica)

Also called Caucasian Rock Cress, Wall Cress, Mountain Cress.

More about caucasian rock cress

About Caucasian Rock Cress

Arabis caucasica · also called Caucasian Rock Cress, Wall Cress · flowering

One of the most widely grown spring rock garden plants, Arabis caucasica produces dense mats of grey-green foliage smothered in fragrant white (or pink, in cultivars) flowers from late winter through spring. Vigorous, easy to grow, and highly frost-hardy. Excellent for dry walls, rock gardens, and border fronts. Cut back hard after flowering to maintain tidiness.

Mature size: 15–30 cm tall, 45–90 cm wide

Watch for — Powdery mildew: Can affect foliage in hot, dry summers with poor air circulation. Improve airflow by cutting plants back after flowering. Resistant cultivars are available. A dilute neem oil or potassium bicarbonate spray can help in persistent cases.

How to tell caucasian rock cress needs repotting

Repotting on a calendar is less reliable than reading the plant. For caucasian rock cress, watch for these signs:

Roots growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot caucasian rock cress

Every 2–3 years, into bone-dry mix. Caucasian Rock Cress's growth habit — vigorous, spreading, mat-forming semi-evergreen perennial — sets the pace. One of the most widely grown spring rock garden plants, Arabis caucasica produces dense mats of grey-green foliage smothered in fragrant white (or pink, in cultivars) flowers from late winter through spring. Vigorous, easy to grow, and highly frost-hardy. Excellent for dry walls, rock gardens, and border fronts. Cut back hard after flowering to maintain tidiness.

What size pot to step caucasian rock cress up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Caucasian Rock Cress stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot caucasian rock cress

Spring or summer, while caucasian rock cress is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting caucasian rock cress

Repot dry. Do not water caucasian rock cress for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty well-drained, lean to moderately fertile, neutral to alkaline soil ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set caucasian rock cress at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep caucasian rock cress completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for caucasian rock cress

Caucasian Rock Cress wants well-drained, lean to moderately fertile, neutral to alkaline soil. Performs best in gritty, well-drained soils. Tolerates poor, stony, and rocky substrates. Lime-tolerant and suited to alkaline conditions (pH 6.5–8.0). Avoid heavy, moisture-retentive clay without significant grit amendment. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting caucasian rock cress — frequently asked questions

How often should you repot caucasian rock cress?

Every 2–3 years, into bone-dry mix for caucasian rock cress. Repot caucasian rock cress every 2–3 years into a snug pot of well-drained, lean to moderately fertile, neutral to alkaline soil, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does caucasian rock cress need?

When is the best time of year to repot caucasian rock cress?

Should you water caucasian rock cress after repotting?

No — not straight away. Repot caucasian rock cress into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise caucasian rock cress after repotting?

Not immediately. Wait about 3 weeks after repotting caucasian rock cress. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.