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Conyza spp.

fleabane

Asteraceae

Warm-temperate and tropical regions worldwide

Attracts Pollinators Deer Resistant Drought Tolerant

Native to North America

SunFull Sun

WaterLow · drought-tolerant

Overview

Conyza spp. is a genus of fast-growing annual and short-lived perennial herbs in the daisy family, with around 50 to 100 species distributed across warm and temperate regions worldwide. Many botanists now merge the genus into Erigeron spp.. Plants form a basal rosette of narrow, often hairy leaves and send up a single erect stem 1-6 feet (0.3-1.8 m) tall, branching near the top into open sprays of many small flower heads. The heads are tiny, with greenish-white to pale yellow disk florets and barely visible rays, opening through summer and autumn and ripening into wind-borne, dandelion-like seed. C. canadensis (Canadian horseweed) and C. bonariensis are widespread weeds of fields, roadsides, and disturbed ground, and several have evolved resistance to common herbicides. The genus tolerates drought, poor soil, and compacted ground, colonizing bare earth quickly from prolific seed. The genus is seldom cultivated and is managed mainly as a weed of crops, gardens, and paving, though some species have recorded traditional medicinal uses. Each plant can produce tens of thousands of seeds, and seedlings emerge over a long season.

Native Range

The genus is distributed across warm-temperate and tropical regions worldwide. Several of the most widespread species originate in the Americas and have naturalized on other continents as weeds.

Suggested Uses

The genus is seldom planted and is encountered mainly as a colonizer of disturbed soil, paving cracks, and field margins. A few species appear in wildflower or naturalistic seed mixes. Most are treated as weeds in gardens and farmland.

How to Identify

Recognized by an erect, leafy, often bristly stem rising from a rosette, branching into open clusters of many small, button-like flower heads. The heads have greenish-white to pale yellow centers and barely visible rays. Fluffy, wind-borne seed follows, much like a small dandelion.

Appearance

Size & Dimensions

Height1' - 6'

Width/Spread6" - 1'6"

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~12 weeks

Summer Fall

Flowering runs through summer and autumn, often July to October, over a long period. The small heads open in succession and quickly set fluffy, wind-dispersed seed. A single plant flowers and seeds over many weeks.

Detailed Descriptions

Flower Description

greenish-white to pale yellow

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 Range5.0 - 8.0(Neutral)

357912

Soil Types

loam sand silt clay rocky

Drainageaverage

Water & Climate

Water Needs

Low

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

These are pioneer plants of open, disturbed ground rather than cultivated subjects. They germinate in full sun on almost any soil, including dry, compacted, and low-fertility sites, and grow without care. In gardens and crops they are controlled by hoeing or pulling seedlings before they flower and set seed. Some populations resist glyphosate and other herbicides, so mechanical removal is often used. Mulching bare soil limits germination. Plants complete their life cycle in a single season.

Pruning

Pruning is not relevant to these weedy plants. Where they are unwanted, the whole plant is pulled or cut at the base before the seed heads ripen. Cutting after flowering still allows some seed to mature, so removal before bloom is more thorough.

⚠️ Toxicity Warning

Unknown

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Annual

Conyza spp.

fleabane

Asteraceae

Warm-temperate and tropical regions worldwide

Attracts Pollinators Deer Resistant Drought Tolerant

Native to North America

SunFull Sun

WaterLow · drought-tolerant

Overview

Native Range

The genus is distributed across warm-temperate and tropical regions worldwide. Several of the most widespread species originate in the Americas and have naturalized on other continents as weeds.