Arabis planisiliqua: complete guide

Overview

Arabis planisiliqua, known as mouse-ear cress or woodland arabis, is a hardy low-growing plant from Europe that naturally inhabits rocky and mountainous areas. With fine silvery-green foliage and abundant white flowers, it forms a perfect ground cover. This plant is ideal for rock gardens, walls and scree gardens where it thrives with minimal care. It's remarkably drought tolerant and adaptable. Its compact, dense growth makes it perfect for alpine gardens and sunny banks.

Appearance and Bloom

Arabis planisiliqua grows low and spreads slowly to maximum 20-30 cm height with much wider spread. The leaves are narrow, finely lobed and form compact rosettes. Foliage is grey-green, sometimes with reddish-purple tints, adding extra charm. From April to May, countless tiny white flowers appear in dense, upright spikes. Each flower is only a few millimeters across but extremely numerous, giving the blooming plant a snowy appearance. The flowers produce long, flat seed pods which give the plant its scientific name planisiliqua (flat pods).

Ideal Location

Arabis planisiliqua thrives best in full sun. Plant in a location with at least 6 hours of direct sunlight daily. It can also grow in part shade but will be less compact and flower less abundantly. Ensure good air circulation around the plant to prevent fungal disease. Avoid wet, dark corners. A south-facing rock or scree garden is ideal.

Soil

Use very well-draining, poor to moderate fertility soil. Arabis actually prefers poor to average soil. Heavy clay soil is completely unsuitable. Sand, gravel and compost in equal parts make a perfect mix. It grows superbly between stones in rock walls. pH range can vary 6.0-8.0. Rich soil makes it lax and lanky - poor nutrition keeps it compact.

Watering

Once planted and established, arabis is drought tolerant and needs little water. It grows fine without additional watering except in extreme dry spells. Water only in very dry periods. It dislikes waterlogged soil so ensure excellent drainage. In winter, it needs practically no water. Overwatering causes root rot and disease.

Pruning

Minimal pruning is needed. After blooming you can lightly trim the plant to maintain compactness. Remove dead flower stems and any long straggly shoots. This helps maintain neat appearance. More cutting back is not needed as the plant naturally grows compact.

Maintenance Calendar

In spring (March-April) flowers appear. This is when you enjoy the display. Little maintenance work is needed. In summer (May-August) the plant rests. In autumn (September-October) growth may restart. In winter (November-February) plants are simply green and dormant.

Winter Hardiness

Arabis planisiliqua is very hardy to at least zone 4 (-30 degrees Celsius) and probably zone 3. In Britain, central Europe and throughout Europe it grows without protection outdoors. It can endure heavy frost. This is a true rock garden plant that also grows in alpine and arctic areas. It tolerates sea wind and pollution better than many other plants.

Companion Plants

Arabis planisiliqua combines beautifully with other alpine and rock garden plants. Combine with saxifrages, sedums, alpine phlox and dwarf geraniums. This grouping creates a stunning low alpine rock wall. Also excellent in troughs and scree gardens.

Closing

Arabis planisiliqua is a reliable, robust plant that perfectly fits rock gardens, alpine gardens and stone walls. With full sun and well-drained soil it flowers reliably each spring. Maintenance is virtually zero - perfect for busy gardeners. Find seeds or plants at garden centers and alpine nurseries. Once planted, it does exactly what it should!

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