Troubleshooting
Alpine Rock Cress problems — and how to fix them
Alpine Rock Cress (Arabis alpina) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Grey mould (Botrytis cinerea)
Can affect foliage and flowers in damp, poorly ventilated conditions, particularly after flowering. Improve airflow by trimming plants back after bloom. Remove any affected plant material promptly.
Self-seeding and invasiveness
Arabis alpina can self-seed prolifically, potentially spreading beyond its intended area. Deadhead or trim spent flowers promptly after bloom to limit unwanted spread in the garden.
Clubroot
As a brassica, susceptible to Plasmodiophora brassicae in acidic, waterlogged soils. Maintain soil pH above 6.5 and rotate planting areas where possible. Infected plants should be removed and not composted.
Prevent alpine rock cress problems before they start
Most alpine rock cress issues are care-mismatch, not bad luck. Dial in the basics:
Alpine Rock Cress problems — FAQ
Why is my alpine rock cress grey mould (botrytis cinerea)?
Can affect foliage and flowers in damp, poorly ventilated conditions, particularly after flowering. Improve airflow by trimming plants back after bloom. Remove any affected plant material promptly.
Why is my alpine rock cress self-seeding and invasiveness?
Arabis alpina can self-seed prolifically, potentially spreading beyond its intended area. Deadhead or trim spent flowers promptly after bloom to limit unwanted spread in the garden.
Why is my alpine rock cress clubroot?
As a brassica, susceptible to Plasmodiophora brassicae in acidic, waterlogged soils. Maintain soil pH above 6.5 and rotate planting areas where possible. Infected plants should be removed and not composted.