What hardiness zones is Iberis sempervirens suitable for?

Iberis sempervirens is suitable for USDA hardiness zones 3, 4, 5, 6, 7, 8, 9.

What are the sun requirements for Iberis sempervirens?

Iberis sempervirens requires Full Sun.

How much water does Iberis sempervirens need?

Iberis sempervirens has Low water needs.

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Perennials

Iberis sempervirens

candytuft

Brassicaceae

Southern Europe, Mediterranean region, western Turkey

At a Glance

TypePerennial

HabitSpreading

FoliageEvergreen

Height6-12 inches (15-30 cm)

Width12-24 inches (30-60 cm)

Maturity2 years

Growing Zones

USDA Hardiness Zones

3 - 9

Zone 3

Zone 4

Zone 5

Zone 6

Zone 7

Zone 8

Zone 9

These zones indicate the coldest temperatures this plant can typically survive.

Frost Tolerancehardy

Key Features

Attracts Pollinators

Attracts Butterflies

Deer Resistant

Drought Tolerant

Container Friendly

Maintenancelow

Overview

A low-growing, evergreen subshrub reaching 6-12 inches (15-30 cm) tall and spreading 12-24 inches (30-60 cm) wide. Stems are woody at the base, becoming semi-herbaceous toward the tips, and root where they contact soil. Leaves are simple, alternate, narrowly spatulate to linear, 0.5-1.5 inches (1.3-3.8 cm) long and 0.1-0.3 inches (3-8 mm) wide, dark glossy green with a slightly leathery texture and smooth margins. Foliage is evergreen, maintaining color through winter in zones 5-9, though leaves may develop bronze to purplish tints in prolonged cold. Flowers appear in dense, flat-topped corymbs 1-2 inches (2.5-5 cm) across at stem tips from mid-April through late May. Individual flowers are small, 0.3-0.5 inches (8-13 mm) across, with four white petals — the outer two petals notably larger than the inner two, giving the flowers a slightly irregular appearance characteristic of the Brassicaceae. After flowering, small round silicles 0.2 inches (5 mm) across develop, turning from green to brown. Plants form dense, cushion-like mats over time. Growth rate is moderate; a single plant fills a 12-18 inch (30-45 cm) area within 2 years. Plants become woody and open at the center after 4-6 years if not pruned. Lifespan is typically 5-8 years in most garden conditions.

Native Range

Native to southern Europe, from the Iberian Peninsula east through the Mediterranean region to western Turkey. Found on rocky limestone slopes, cliffs, and open scrubby hillsides at 300-2,000 feet (100-600 m) elevation in well-drained, alkaline soils.

Suggested Uses

Commonly planted along border edges, atop rock walls, and in rock gardens at 12-18 inch (30-45 cm) spacing. Used as a groundcover on well-drained slopes and as an edging plant along pathways. The trailing habit suits stone wall plantings where stems can cascade 6-12 inches (15-30 cm) over edges.

How to Identify

Identified by its low, dense, cushion-forming habit with narrow, dark green, glossy evergreen leaves 0.5-1.5 inches (1.3-3.8 cm) long arranged alternately on semi-woody stems. Flowers in dense, flat-topped corymbs of white four-petaled flowers, with the outer two petals distinctly larger than the inner two — a characteristic of the Brassicaceae. The combination of evergreen subshrub habit, spatulate leaves, and asymmetric white flowers in flat-topped clusters is diagnostic.

Appearance

Size & Dimensions

Height6" - 1'

Width/Spread1' - 2'

Reaches mature size in approximately 2 years

Colors

Flower Colors

white

Foliage Colors

green

Bloom Information

Bloom Period

~4 weeks

Spring

Flowers from mid-April through late May in zones 5-7. In zones 8-9, flowering may begin in late March. Peak bloom lasts 3-4 weeks. Individual corymbs remain in flower for 10-14 days. A light secondary flush of bloom sometimes occurs in early fall if plants are sheared after the main flowering period. In cool maritime climates, bloom may extend into early June.

Detailed Descriptions

Flower Description

White

Foliage Description

Dark glossy green; bronze to purplish tints in prolonged cold

Growing Conditions

Sun Requirements

Full Sun

Partial Shade

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

loamsandchalkrocky

Drainage

well drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

1-2 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Water weekly during the first growing season. Established plants tolerate moderate drought and require supplemental water only during extended dry periods exceeding 3 weeks. Overwatering and poorly drained soils lead to root rot, the primary cause of plant loss. Apply a thin layer of gravel or stone chip mulch 1 inch (2.5 cm) deep rather than organic mulch, which retains excessive moisture around the crown. Fertilization is typically unnecessary in reasonably fertile soils; excess nitrogen promotes leggy growth at the expense of flowers. Crown rot may develop in humid climates with poor air circulation at the base. Slugs and snails may feed on new growth in spring in the Pacific Northwest.

Pruning

Shear plants back by one-third immediately after flowering in late May to early June. This promotes dense, compact regrowth and may stimulate a secondary fall bloom. Without post-bloom pruning, plants become woody and open at the center within 3-4 years. Do not prune into old woody growth below green foliage, as this rarely regenerates. Replace plants every 5-8 years when they become excessively woody despite regular pruning.

Pruning Schedule

late spring

Maintenance Level

low

Container Growing

✓ Suitable for container growing

Minimum container size: 3 gallons

⚠️ Toxicity Warning

Non-toxic