At a Glance
TypePerennial
HabitUpright
FoliageSemi-evergreen
Height24-48 inches (60-120 cm)
Width24-36 inches (60-90 cm)
Maturity2 years
Growing Zones
USDA Hardiness Zones
8 - 10These zones indicate the coldest temperatures this plant can typically survive.
What's my zone? →Frost Tolerancehardy
Overview
Inula viscosa (syn. Dittrichia viscosa) is a semi-woody, shrubby perennial in the Asteraceae family, growing 24–48 inches (60–120 cm) tall and 24–36 inches (60–90 cm) wide with an upright, bushy habit. The entire plant is densely glandular-sticky (viscid), coated in a resinous exudate with a strong, pungent, camphor-like scent detectable from several feet. Stems are erect, woody at the base, profusely branched in the upper half. Leaves are alternate, lanceolate, 1.5–4 inches (4–10 cm) long, sessile, clasping the stem at the base, with a wavy margin, bright green and sticky on both surfaces. Flower heads are 0.5–0.75 inch (12–18 mm) across, with bright yellow ray florets and a yellow disc, borne in large, branching terminal panicles producing hundreds of heads per plant. The species blooms in late summer to autumn — a period when few other shrubby perennials of Mediterranean habitats are in flower — making it a critical late-season nectar source for migrating insects. Native to the Mediterranean basin, where it is one of the most common and conspicuous plants of disturbed ground, roadsides, and abandoned agricultural land. Tolerates extreme drought, poor soil, salt spray, and pollution. Considered invasive in parts of South Africa and Australia. The sticky glandular exudate traps small insects on the stems and leaves, though the plant is not carnivorous.
Native Range
Inula viscosa is native across the Mediterranean basin, from Portugal and Morocco east through the entire Mediterranean littoral to Turkey, the Levant, and Iran. It occurs on disturbed ground, roadsides, abandoned fields, riverbanks, and coastal habitats from sea level to approximately 3,000 feet (900 m).Suggested Uses
Planted in dry Mediterranean-style gardens, gravel gardens, and coastal plantings. The late-autumn bloom provides colour and nectar when few other plants are flowering. In Mediterranean climates, used for erosion control on dry slopes and disturbed ground. An important plant for late-season pollinator support. Not suited to irrigated garden borders or heavy clay soils.How to Identify
Appearance
Size & Dimensions
Height2' - 4'
Width/Spread2' - 3'
Reaches mature size in approximately 2 years
Bloom Information
Flower heads open from August through November — one of the latest-flowering Mediterranean shrubs. The branching panicles produce hundreds of small yellow heads progressively over 8–12 weeks. Peak bloom is September–October. Pollinated by bees, hoverflies, and butterflies; an important late-season nectar source in Mediterranean ecosystems.Detailed Descriptions
Foliage Description
Bright green, sticky-glandularGrowing Conditions
Sun Requirements
Requires 6-12 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
Care & Maintenance
Care Guide
Plant in full sun in any well-drained soil with a pH of 6.0–8.5. Tolerates poor, rocky, gravelly, and calcareous soils. Space 24–30 inches (60–75 cm) apart. Do not fertilise. Water sparingly — drought-tolerant once established and resents summer irrigation in heavy soils. In the Pacific Northwest, hardy only in the mildest zones (8b–9) with sharp drainage. In zones 7–8a, treat as an annual or overwinter potted plants in a cold greenhouse. The sticky exudate stains hands and clothing — handle with care.Pruning
Cut back hard to 6–8 inches (15–20 cm) in early spring (March) to maintain a compact shape and prevent legginess. The species regenerates from the woody base. Remove spent flower stems in late autumn or leave for winter structural interest. Without annual hard pruning, plants become leggy and open within 2–3 years.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
early spring
Maintenance Level
lowContainer Growing
✓ Suitable for container growing
Minimum container size: 5 gallons