Dittrichia spp.

stinkwort

Asteraceae

Mediterranean Basin and western Asia

Attracts Pollinators Attracts Butterflies Deer Resistant Drought Tolerant Fragrant (strong)

SunFull Sun

WaterLow · drought-tolerant

HardinessZones 8–10

Overview

Dittrichia spp. is a genus of two species of aromatic, sticky-glandular herbs and subshrubs in the daisy family (Asteraceae), native to the Mediterranean region and western Asia. Plants are densely covered in sticky glandular hairs that give off a strong camphor- or turpentine-like scent and coat the foliage in a resinous film. D. graveolens, stinkwort, is a much-branched annual 8-28 inches (20-70 cm) tall, while D. viscosa, false yellowhead, is a woody-based perennial reaching 1.6-4.3 feet (0.5-1.3 m). Both bear narrow, alternate leaves and many small yellow daisy flower heads with short rays, opening in late summer and autumn. Seeds carry a pappus of hairs and disperse on wind, clothing, and animals. D. graveolens has spread as an invasive weed along roadsides and disturbed ground in Australia, California, and elsewhere. The sticky foliage can cause skin irritation and taints the milk and meat of livestock that eat it.

Native Range

Dittrichia spp. is native to the Mediterranean Basin and western Asia, in dry, open, disturbed ground, field margins, and coastal scrub. D. graveolens has naturalised widely as a weed in Australia, North America, and other warm-temperate regions.

Suggested Uses

D. viscosa is sometimes grown in dry Mediterranean and gravel gardens for late-season yellow flowers and aromatic foliage, and is used in habitat plantings for late pollinators. D. graveolens is treated as a weed and is rarely planted.

How to Identify

Recognised by sticky, glandular, strongly aromatic foliage and many small yellow daisy flower heads with short rays, opening in late summer and autumn. D. graveolens is a low, much-branched aromatic annual, while D. viscosa is a taller woody-based perennial. The resinous camphor-like smell and sticky leaves are reliable field checks.

Appearance

Size & Dimensions

Height8" - 4'4"

Width/Spread1' - 3'

Colors

Flower Colors

yellow

Foliage Colors

green

Bloom Information

Bloom Period

~10 weeks

Summer Fall

Flowering comes late in the season, from late summer into autumn, when stems carry many small yellow daisy heads. The late bloom lets the plants set seed after summer-flowering vegetation has finished. Wind- and animal-dispersed seed follows quickly.

Detailed Descriptions

Foliage Description

green, sticky

Growing Conditions

Sun Requirements

SunFull Sun

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

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

sand loam clay rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

tender

Time to Maturity

1-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Dittrichia spp. grows in full sun in dry, poor, well-drained soils, including disturbed, gravelly, saline, and roadside ground. Plants tolerate heat and drought and grow fast in open, sunny sites, with D. graveolens completing its life cycle in a single season. The genus copes with low fertility and compacted soils that limit other plants. D. graveolens self-seeds heavily and spreads quickly, which underlies its weed status outside its native range. The perennial D. viscosa resprouts from a woody base after cutting or frost. The sticky foliage can irritate skin on contact.

Pruning

The annual D. graveolens is pulled or cut before it sets seed to limit spread, rather than pruned. On the perennial D. viscosa, stems can be cut back after flowering to keep a compact shape, and it regrows from the woody base. Spent growth and seed heads are removed before seed disperses.