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Dittrichia graveolens

stinkwort

Asteraceae

Mediterranean region and western Asia

Attracts Pollinators Deer Resistant Drought Tolerant Fragrant (strong)

SunFull Sun

WaterVery Low · drought-tolerant

Overview

Dittrichia graveolens is a strongly aromatic, glandular-hairy annual in the daisy family growing 8-36 inches (20-90 cm) tall, with a bushy, much-branched, pyramidal form. The narrow, sticky leaves are 0.5-2 inches (1.3-5 cm) long and release a heavy, camphor-like odor when touched, which gives the plant its name. Late in the season, from late summer into late fall, it produces many small yellow flower heads about 0.2-0.3 inch (5-8 mm) wide, each with short ray florets, scattered along the branch tips. Native to the Mediterranean region and western Asia, it has spread as an invasive weed in California, Oregon, Australia, and elsewhere, colonizing roadsides, fields, disturbed ground, and increasingly highway shoulders and drainage channels. D. graveolens germinates late, flowers and seeds in autumn after most other annuals have finished, and tolerates dry, compacted, and saline soils. Its sticky resins can cause skin irritation and allergic dermatitis, and the seed bristles and resins can injure or sicken grazing livestock. It is listed as a noxious or invasive weed in several regions.

Native Range

Native to the Mediterranean region, North Africa, and western Asia. It has become an invasive weed in California, Oregon, parts of Australia, and other areas with dry summers, spreading along roadsides, fields, and disturbed ground.

Suggested Uses

This species is not grown as a garden or ornamental plant. It is managed almost entirely as an invasive and noxious weed along roadsides, in fields, and on disturbed land, where control efforts focus on preventing seed set. It has no recognized landscape, forage, or wildlife use and is removed where it appears.

How to Identify

Identify it by a bushy, pyramidal annual with narrow, sticky, glandular leaves that give off a strong camphor- or turpentine-like smell when crushed. Numerous small yellow daisy-like heads 0.2-0.3 inch (5-8 mm) wide appear late in the season along the upper branches. The heavy odor, sticky resinous foliage, and very late autumn bloom together identify it.

Appearance

Size & Dimensions

Height8" - 3'

Width/Spread8" - 2'

Colors

Flower Colors

yellow

Foliage Colors

green

Bloom Information

Bloom Period

~10 weeks

Summer Fall

Flowering comes very late in the year, from late summer through late fall, often into November in mild climates, after most summer annuals have set seed. The small yellow heads open over several weeks and quickly form bristly seeds. The late season helps the plant spread before winter.

Detailed Descriptions

Foliage Description

green

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 - 8.5(Alkaline)

357912

Soil Types

clay loam sand rocky

Drainagewell drained

Water & Climate

Water Needs

Very Low

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

D. graveolens is an annual that germinates in late spring or summer, grows through the dry season, and flowers in autumn. It tolerates full sun, drought, heat, and poor, compacted, or saline soils, which lets it colonize roadsides and hard ground. It needs no cultivation and is almost never planted on purpose. Where it is invasive, removing plants before seed set is the main control. Its sticky resins can irritate skin on contact, and the seeds can injure grazing animals. After seeding it dies, but its abundant seed builds a lasting seed bank.

Pruning

Pruning does not apply to this weedy annual. Cutting or pulling plants before the flowers form seed is the main way to limit its spread, and removing whole plants is more reliable than cutting, which can prompt regrowth.