Common ragweed
Ambrosia artemisiifolia · Asteraceae
The gardener's calendar
Ideal time to plant common ragweed: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Asteraceae
- Type
- Annual herbaceous plant
- Foliage
- Deciduous (annual)
- Flowering
- July to October
- Mature size
- 30 to 150 cm in height
- Growth
- Fast
- Hardiness
- Low hardiness (annual)
- Origin
- North America
Care
Exposure
Annual ragweed thrives in full sun, where it develops vigorous growth. It also tolerates partially shaded areas but will flower less abundantly. Avoid overly confined locations that would promote stagnant humidity.
Watering
Water moderately, keeping the soil slightly moist without waterlogging. This plant adapts well to dry periods once established. Excess water promotes root rot.
Soil
Ragweed is not demanding regarding soil type. It grows on poor, compacted, or even disturbed terrain. Well-drained soil remains preferable to avoid moisture accumulation.
Pruning and removal
No pruning is necessary. To control its spread, remove faded flowers before seed production. Eliminate the plant entirely at the end of the season to prevent dispersal.
Fertilizer
No fertilizer is needed. This pioneer plant tolerates poor soils and grows rapidly without particular amendments.
Pests and diseases
Ragweed is generally robust. It can be affected by aphids or spider mites in hot and dry conditions. Monitor foliage and intervene if necessary with soapy water sprays.
Did you know?
Annual ragweed has become one of Europe's most problematic invasive species since its accidental arrival from North America, particularly through sunflower seed imports. Its pollen is extremely allergenic and affects millions of people each autumn, explaining the eradication campaigns conducted by health authorities. As an informed gardener, you are advised not to cultivate it intentionally and to report it if it appears spontaneously.
Where to buy it
Plant in spring or early autumn, avoiding spells of intense heat. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September.
Add this plant to my garden →Plants from the same family
- SunflowerHelianthus annuus
- YarrowAchillea millefolium
- Ox-eye daisyLeucanthemum vulgare
- SneezewortAchillea ptarmica
- Canadian goldenrodSolidago canadensis
- WormwoodArtemisia absinthium
Tips generated and checked by Viridia — adapt them to your local climate.