Shasta Knotweed
Polygonum shastense
- Native to:
- United States
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Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Polygonaceae
- Genus:
- Polygonum
- Species:
- Polygonum shastense
- USDA Symbol:
- POSH
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Shrub , Subshrub
- Height:
- 30 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Medium
- Bloom Months:
- jun,jul,aug,sep
- Bloom Colors:
- white, pink
- Ground Cover:
- Yes
Wildlife Benefits
- Butterflies & Moths:
- ★☆☆☆☆ Documented Lepidoptera association (GBIF)
Garden & Ecology Notes
- Wildlife Value:
- butterflies, small mammals
Soil Requirements
- Soil Type:
- rocky, well-drained, nutrient-poor soil
- pH:
- 5.5 - 7.5 (slightly acidic to neutral)
- Drainage:
- excellent drainage required
- Moisture:
- dry to moderate
- Notes:
- native to mountainous regions with sparse vegetation
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 14–42 days
The above propagation data sourced from Claude AI
Pre-treatment: Seeds are placed into fine mesh bags and soaked in a 1% hydrogen peroxide (3:1 water/3% hydrogen peroxide) for 24 hours, then rinsed and placed in water for an additional 24 hours. Seeds are layered in peat and placed into cold stratification (33.8 to 37.4 °F) for 60 days. Check seeds in peat weekly and treat with 1% hydrogen peroxide if mold is evident.
Source: npn.rngr.net