Overview
Erigeron sumatrensis, formerly placed in Conyza spp., is an erect annual or biennial herb growing 20-80 in (50-200 cm) tall, with greyish, densely hairy stems that branch in the upper part. The grey-green leaves are 1.5-4 in (4-10 cm) long, lance-shaped, hairy, and toothed, becoming smaller up the stem. From summer into autumn the plant carries many small flowerheads about 0.2 in (4-6 mm) across in a large, branched, roughly pyramidal cluster, each head with tiny whitish to cream florets and only minute ray florets. Each head ripens into a tuft of small seeds carried on slender bristles that disperse widely on the wind. A single plant can produce tens of thousands of seeds and establishes quickly on bare ground. It is a weed of crops, orchards, roadsides, and waste places across warm-temperate and subtropical regions, and many populations resist glyphosate and other herbicides. It completes its life cycle in a single season and relies on heavy seeding rather than perennial regrowth.
Native Range
Native to South America. It has spread as a weed to North America, Europe, Africa, Asia, and Australia, naturalising on disturbed, cultivated, and waste ground in warm regions.Suggested Uses
This species is not cultivated as an ornamental and is treated as an agricultural and environmental weed. It has no recognised horticultural use.How to Identify
Appearance
Size & Dimensions
Height1'8" - 6'8"
Width/Spread8" - 1'8"
Bloom Information
Detailed Descriptions
Foliage Description
grey-greenGrowing 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
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Erigeron sumatrensis grows in full sun on poor, dry, compacted, and disturbed soils and tolerates heat and drought once established. It germinates in flushes after rain and develops a shallow, fibrous root system. The plant needs no cultivation and is managed as a weed rather than grown. Seedlings emerge readily on bare ground and grow quickly to a tall flowering stem within a few months. Dense stands compete with crops for water and light, and herbicide resistance makes chemical control difficult in many areas.Pruning
No pruning is required for this weed. Plants are cut, hoed, or pulled before the flowerheads mature to limit the large output of wind-blown seed. Removing plants while young controls them better than cutting tall, seeding stems.⚠️ Toxicity Warning
UnknownPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
spring
Days to Maturity
90–150 days
Plant Spacing
12 inches