Open Grow Guide

Annual Ragweed (Ambrosia artemisiifolia)

Formerly Ambrosia elatior, Ambrosia elata, Iva monophylla

By Open Grow Guide Updated

Give annual ragweed (Ambrosia artemisiifolia) full sun, which is its preferred light, and expect it to want dry soil. It also tolerates part shade and full shade. Its soil moisture is listed as dry, and it tolerates drought. Toxicity to cats and to dogs is not documented on this page.

annual ragweed (Ambrosia artemisiifolia), whole plant

Photo: Jpve, CC BY-SA 4.0 via Wikimedia Commons

Quick facts

Each value is the cited value from the sources listed at the end of this page.
Light Full sun, part shade and full shade (full sun preferred)1233
Water Dry13
Soil Well drained and occasionally dry31 source
Size 4–6 ft (1.22–1.83 m) × 3–4 ft (0.91–1.22 m)2531 source
Growth rate Rapid23
Bloom Jun–Nov, Green, brown and yellow311 source
Cats Not documented by major sources
Dogs Not documented by major sources
Native range ABT, ALA, ARI, ARK, ASK, BRC, CAL, CNT, COL, DEL, FLA, GEO, IDA, ILL, INI, IOW, KAN, KTY, LOU, MAI, MAN, MAS, MIC, MIN, MNT, MRY, MSI, MSO, NBR, NCA, NDA, NEB, NEV, NSC, NWH, NWJ, NWM, NWT, NWY, OHI, OKL, ONT, ORE, PEI, PEN, QUE, RHO, SAS, SCA, TEN, TEX, UTA, VER, VRG, WAS, WDC, WIS, WVA, WYO6
Family Asteraceae

How much light does an Annual Ragweed need?

Annual ragweed tolerates a full range of light, from full sun through part shade to full shade. Full sun is the preferred setting for this plant. Common ragweed grows in full sun and in a wide range of soil conditions. The Lady Bird Johnson Wildflower Center lists its light requirement as sun, part shade and shade.

  • LightFull sun, part shade and full shade (full sun preferred)1233

How often to water an Annual Ragweed

Annual ragweed is listed for dry soil moisture. The Lady Bird Johnson Wildflower Center records dry as its soil moisture, and the record gives dry as both the lowest and the highest level. NC State Extension describes the plant as drought tolerant and poor soil tolerant. Soil that drains well and is occasionally dry also matches the drainage listed for this plant.

  • WaterDry13

Best soil for an Annual Ragweed

Good drainage and occasionally dry conditions are the soil traits listed for annual ragweed. Its drainage listing has two parts: well drained, and occasionally dry. NC State Extension describes the plant as drought and poor soil tolerant. Common ragweed grows in a wide range of soil conditions. The water record for this species also lists dry soil moisture. No soil pH range is documented for this plant. The facts on file name no other soil trait.

  • Soil drainageWell drained and occasionally dry33

How to propagate an Annual Ragweed

You propagate annual ragweed (Ambrosia artemisiifolia) from seed, and seed is the only propagation method listed for this plant. The NC State Extension Gardener Plant Toolbox names seed under propagation. The propagation record for this species contains one entry, which is seed. No other method appears in it.

  • PropagationSeed3

Common problems

The pests listed for annual ragweed include Corythucha marmorata, Cuerna costalis, Diabrotica virgifera zeae and Euwallacea kuroshio. Lepyronia quadrangularis, Oncometopia nigricans, Oncometopia orbona, Phenacoccus miruku and Ditylenchus dipsaci are also listed. Three diseases are listed as well: Phymatotrichopsis omnivora, Xylella fastidiosa and Orthotospovirus tomatomaculae.

  • Common pestscorythucha marmorata, cuerna costalis, diabrotica virgifera zeae, euwallacea kuroshio, lepyronia quadrangularis, oncometopia nigricans, oncometopia orbona, phenacoccus miruku and ditylenchus dipsaci4
  • Common diseasesphymatotrichopsis omnivora, xylella fastidiosa and orthotospovirus tomatomaculae4
Pests and diseases recorded for this plant by the sources listed at the end of this page.
ProblemKind
Corythucha marmorata Pest
Cuerna costalis Pest
Diabrotica virgifera zeae Pest
Euwallacea kuroshio Pest
Lepyronia quadrangularis Pest
Oncometopia nigricans Pest
Oncometopia orbona Pest
Phenacoccus miruku Pest
Ditylenchus dipsaci Pest
Phymatotrichopsis omnivora Disease
Xylella fastidiosa Disease
Orthotospovirus tomatomaculae Disease

Is Annual Ragweed toxic to cats and dogs?

Not documented by major sources Not documented by major sources

Recommended supplies

  • Soil: a free-draining mix, and a pot with a drainage hole.

Questions and answers

How tall does annual ragweed grow?
Annual ragweed reaches about 4 to 6 ft (1.22–1.83 m) tall, with a spread of 3 to 4 ft (0.91–1.22 m). Clemson Cooperative Extension says it can reach four to six feet tall. Its growth rate is rapid.
What color are annual ragweed flowers, and when do they bloom?
The flowers are green, brown and yellow. NC State Extension describes each small flower as green, turning yellow-green and then brown as it matures. The bloom season in the listing runs from June to November.
Is annual ragweed native to the United States?
Annual ragweed is native in the lower 48 US states and introduced in Hawaii. Its native range is recorded as a list of region codes, from ABT to WYO.

Sources

  1. Lady Bird Johnson Wildflower Center. https://www.wildflower.org/plants/result.php?id_plant=amar2. Accessed 14 October 2026.
  2. Clemson Cooperative Extension HGIC. https://hgic.clemson.edu/weed-of-the-month-common-ragweed/. Accessed 14 October 2026.
  3. NC State Extension Gardener Plant Toolbox. https://plants.ces.ncsu.edu/plants/ambrosia-artemisiifolia/. Accessed 14 October 2026.
  4. EPPO Global Database. https://gd.eppo.int/taxon/AMBEL/pests. Accessed 14 October 2026.
  5. Clemson Cooperative Extension HGIC. https://hgic.clemson.edu/factsheet/goldenrod-ragweed/. Accessed 14 October 2026.
  6. Royal Botanic Gardens, Kew (World Checklist of Vascular Plants). https://sftp.kew.org/pub/data-repositories/WCVP/wcvp.zip. Accessed 4 June 2026.

How this page was made

  • Written with AI assistance from the sources listed on this page. AI is never the source of a fact.

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