Iberis saxatilis aka Candytuft

Iberis saxatilis is known as rock candytuft or alpine candytuft. It belongs to the cabbage family, Brassicaceae. Its native range runs from Spain to Switzerland and Crimea. It grows in temperate regions and is not native to Britain or Ireland. This low perennial has a woody base and a shrubby form. It spreads into a small mound rather than growing tall.

Plants reach about 0.25–0.5 feet [0.08–0.15 metres] high. The mound spans about 0.8–1.5 feet [0.25–0.46 metres], sometimes more. Leaves stay on the plant in mild winters. In colder places, it keeps only some of its leaves. Harsh winters can leave the foliage thin or untidy. Stems can form roots where they touch the soil. These rooted sections can stay in place or move elsewhere.

Flowers appear from March to May, with a dense spring display. Each small flower has four white petals. Purple tints develop as the flowers age. The blooms form flat clusters called corymbs. Their show suits rock gardens, alpine gardens, and small sunny beds. Plants also suit pots and the edges of paths and borders. Their spreading stems can trail over a wall. They provide low ground cover where space is tight. The flowers attract butterflies, and the plant also draws birds.

Give this plant full sun and soil that drains well. It accepts some shade but makes fewer flowers there. Soil with moderate moisture suits it, though it also tolerates drought. Drainage matters more than a rich supply of water. Missouri Botanical Garden lists it for USDA zones 3–8. After bloom, shorten stems by about one third. This helps keep the mound compact and prompts fresh growth. In cold areas, a light cover of evergreen branches can help. Snow cover can also shield the leaves from winter damage.

Wet soil can cause crown rot and kill whole plantings. Club root can leave plants small and weak. Other possible diseases include downy mildew, powdery mildew, and gray mold. Rust and fungal leaf spots may also occur. Watch for slugs, snails, and caterpillars. Cold-weather sun scorch and drying can harm leaves that remain green. Deer and rabbits tend to leave this plant alone.