Marshpepper Knotweed
Persicaria hydropiper
- Native to:
- Afghanistan, Albania, Algeria, Andaman Is., Australia, Austria, Azores, Baltic States, Bangladesh, Belarus, Belgium, Bulgaria, China, Corse, Czechia-Slovakia, Denmark, Finland, France, Germany, Great Britain, Greece, Hainan, Hungary, India, Iran, Ireland, Italy, Japan, Jawa, Kazakhstan, Kirgizstan, Korea, Krym, Kuril Is., Madeira, Malaya, Morocco, Myanmar, Nansei-shoto, Nepal, Netherlands, Nicobar Is., North Caucasus, Norway, NW. Balkan Pen., Ogasawara-shoto, Pakistan, Philippines, Poland, Portugal, Romania, Russia, Sardegna, Sicilia, Spain, Sri Lanka, Sumatera, Sweden, Switzerland, Tadzhikistan, Taiwan, Thailand, Transcaucasus, Türkiye, Türkiye-in-Europe, Ukraine, Uzbekistan, Vietnam
Natthager
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Polygonaceae
- Genus:
- Persicaria
- Species:
- Persicaria hydropiper
- USDA Symbol:
- POHY
Growth Characteristics
- Life Cycle:
- Annual
- Growth Habit:
- Forb/herb
- Height:
- 90 cm
- Light Requirements:
- Full Sun
- Drought Tolerance:
- Low
- Bloom Months:
- jun,jul,aug,sep,oct
- Bloom Colors:
- greenish-white, pink
Host Plant for Caterpillars
Crocus Geometer (Xanthotype sospeta), Flounced Chestnut (Agrochola helvola), Green Cloverworm Moth (Hypena scabra), Prochoerodes transversata, Simyra henrici, Smeared Dagger Moth (Acronicta oblinita), stalk borer moth (Papaipema nebris), The Gem (Orthonama obstipata), Variable Carpet Moth (Orthonama centrostrigaria), Yellow-legged Tiger Moth (Haematopis grataria), zebra caterpillar moth (Melanchra picta)
Garden & Ecology Notes
- Wildlife Value:
- birds, butterflies
Soil Requirements
- Soil Type:
- rich, moist, nutrient-rich soil
- pH:
- 5.5 - 7.0 (slightly acidic to neutral)
- Drainage:
- tolerates poor drainage
- Moisture:
- consistently moist
- Notes:
- Often found in wetlands and along water bodies
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 14–30 days
- Notes:
- Seeds benefit from cold stratification; surface sow on moist soil.