Biennial Wormwood
Artemisia biennis
Matt Lavin (www.flickr.com) from Bozeman, Montana, USA
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Asteraceae
- Genus:
- Artemisia
- Species:
- Artemisia biennis
- USDA Symbol:
- ARBI2
Growth Characteristics
- Life Cycle:
- Annual | Biennial
- Growth Habit:
- Forb/herb
- Height:
- 300 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Medium
- Bloom Months:
- jul,aug,sep
- Bloom Colors:
- green, yellow
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
Keystone Species Ranking
- Caterpillar Keystone:
- ★★★★☆ Butterfly & moth species supported by this genus (NWF)
Garden & Ecology Notes
- Wildlife Value:
- birds
- Deer Resistant:
- Yes
- Fragrant:
- Yes
Soil Requirements
- Soil Type:
- sandy, well-drained, nutrient-poor soil
- pH:
- 6.0 - 8.0 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- Commonly found in disturbed areas and roadsides
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 7–21 days
- Notes:
- Seeds require light for germination and benefit from cold stratification. Surface sow or barely cover seeds.
The above propagation data sourced from Claude AI
Pre-treatment: 5 month outdoor cold, moist stratification
Establishment: Seeds are hand collected in mid September when achenes turn grey and are easily removed from the disk. Seeds are collected in paper bags and kept in a well ventilated drying shed prior to cleaning. A. biennis is a biennial which occupies very sandy soils from low to high elevations, throughout the Pacific Northwest, but is widely introduced elsewhere in the United States as a weed, where it is found in waste places.
Source: npn.rngr.net