Arabis blepharophylla aka Rose Rockcress

Arabis blepharophylla is an evergreen perennial native to California. It belongs to Brassicaceae, the mustard family. Gardeners know it as rose rock cress or rosy-flowered rock cress. It grows as a low mat or rounded mound. Its foliage stays green through the year. This low form suits rock gardens, gravel beds, and border edges. Plants reach their full size in two to five years.

The RHS gives a garden height of 0.3–1.6 feet [0.1–0.5 metres]. Its spread falls within the same range. Loose rosettes hold mid-green leaves, broadest near their tips. Some leaves have toothed edges, while others have smooth margins. The flowers have a deep pink colour with purple tones. They carry scent and grow in racemes. Flowering runs from late spring into early summer. The blooms rise above the leafy mats during this season.

Grow this species in full sun and well-drained soil. The RHS lists chalk, clay, loam, and sand as suitable. It accepts acid, neutral, and alkaline soils. It also tolerates poor ground, heat, and dry spells. Good drainage matters, and plants need protection from winter wet. Both open and sheltered sites can suit it. South-, east-, and west-facing positions are listed as suitable. The RHS rates its hardiness H5 for UK conditions. This covers winter lows around 5–14°F [−15 to −10°C].

Its compact form fits pots on patios as well as beds. Banks and slopes offer further planting sites. Trim plants after bloom to keep their shape compact. Propagate them from seed or take softwood cuttings. Division in summer provides another way to make new plants. For alpine-house culture, use equal shares of loam, leaf mould, and sharp sand. Water well during active growth, then reduce watering in winter. This seasonal care differs from leaving roots wet through cold weather.

Check plants for aphids, gall midge, and flea beetles. These pests may attack the species, according to the RHS. Downy mildews and white blister are also possible problems. The supplied evidence gives no details about fruit or seed appearance. It also does not establish edible uses or toxicity. Those gaps do not support treating the plant as food or declaring it safe.