Silver Bur Ragweed
Ambrosia chamissonis
- Native to:
- Canada, Chile, Mexico, United States
Eric in SF
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Asteraceae
- Genus:
- Ambrosia
- Species:
- Ambrosia chamissonis
- USDA Symbol:
- AMCH4
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Forb/herb , Shrub , Subshrub
- Height:
- 100 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- High
- Bloom Months:
- jul,aug,sep,oct
- Bloom Colors:
- greenish-yellow
- Ground Cover:
- Yes
Wildlife Benefits
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
- Caterpillars:
- ★☆☆☆☆ Recorded caterpillar host plant (HOSTS Database)
Host Plant for Caterpillars
Western tussock moth (Orgyia vetusta)
Garden & Ecology Notes
- Wildlife Value:
- birds, butterflies
- Deer Resistant:
- Yes
- Salt Tolerant:
- 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 coastal dunes and sandy beaches
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 14–30 days
- Notes:
- Seeds benefit from cold stratification for 30-60 days to break dormancy.
Pre-treatment: Seeds are soaked for 24 hours in water, then placed in a cold stratification in the refrigerator for 2 months. Check seeds periodically for radicle emergence.
Establishment: Seeds are collected between April 15th to December 30th. Mature inflorescences are brown. Seeds are burr like, 5 to 10 mm long, greyish brown. Seeds drop from plant when mature. A. chamissonis is found on coastal beaches and dunes, from sea level to 50 feet elevation; from British Columbia south to central coastal California.
Source: npn.rngr.net