Narrowleaf Knotweed

Polygonum bellardii

Native to:
Albania, Algeria, Austria, Baleares, Belarus, Bulgaria, Canada, Corse, Czechia-Slovakia, East Aegean Is., Egypt, France, Greece, Hungary, Iran, Italy, Kazakhstan, Krym, Lebanon-Syria, Libya, Madeira, Morocco, North Caucasus, NW. Balkan Pen., Palestine, Romania, Russia, Sardegna, Sicilia, Sinai, Spain, Tadzhikistan, Transcaucasus, Tunisia, Türkiye, Türkiye-in-Europe, Ukraine, Uzbekistan

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Polygonaceae
Genus:
Polygonum
Species:
Polygonum bellardii
USDA Symbol:
POBE

Growth Characteristics

Life Cycle:
Annual
Growth Habit:
Forb/herb
Height:
60 cm
Light Requirements:
Full Sun
Drought Tolerance:
Low
Bloom Months:
jun,jul,aug,sep
Bloom Colors:
white, pink

Host Plant for Caterpillars

Bronzed Cutworm (Nephelodes minians), Dark-barred Twin-spot Carpet (Xanthorhoe ferrugata), Flounced Chestnut (Agrochola helvola), Grammia virguncula, Lucerne Moth (Nomophila nearctica), many-lined carpet moth (Anticlea multiferata), Ornate Tiger Moth (Grammia ornata), sentinel wave moth (Scopula sentinaria), underworld dart (Agrotis subterranea), Variable Carpet Moth (Orthonama centrostrigaria), Variegated cutworm (Peridroma saucia), Yellow-legged Tiger Moth (Haematopis grataria), Acmon blue (Plebejus acmon), Epidemia helloides

Garden & Ecology Notes

Wildlife Value:
birds

Soil Requirements

Soil Type:
sandy, well-drained, nutrient-poor soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
often found in disturbed areas and open habitats

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
14–28 days
Notes:
Seeds germinate readily in moist conditions after cold stratification.

The above propagation data sourced from Claude AI