Shore knotweed Plant Care
Polygonum arenarium Waldst. & Kit.
Updated · Sources · How we source care data
Polygonum arenarium, the lesser red-knotgrass or European knotweed, is a species of flowering plant in the family Polygonaceae. It is native to Morocco, France, the former Czechoslovakia, Hungary, southeastern and eastern Europe, the Caucasus, Turkey, the Levant, Iraq, Iran, and Central Asia, and it has been introduced to Argentina, the British Isles, Germany, the Baltic States, and central European Russia.
Full sun to part shade
At a glance
How do you care for Shore knotweed?
Shore knotweed grows best in full sun to part shade.
What Is the Shore knotweed?
Shore knotweed (Polygonum arenarium) belongs to the Polygonaceae family within the Polygonum genus. Shore knotweed is native to disturbed habitats.
Shore knotweed displays a spreading ground cover growth habit, reaching up to tall with a spread of approximately . Shore knotweed produces small, inconspicuous flowers in clusters.
What Light Does the Shore knotweed Need?
Shore knotweed thrives in full sun to part shade.
Light Requirement
Full sun to part shade
What Soil Mix Works Best for a Shore knotweed?
Moist, fertile soil with good drainage. Good drainage is essential for Shore knotweed to prevent waterlogging, which leads to root rot and fungal issues.
How Do You Repot a Shore knotweed?
Divide and replant every 2-3 years. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Shore knotweed?
Shore knotweed can be propagated through seeds, division.
Is the Shore knotweed Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Shore knotweed, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Shore knotweed?
Shore knotweed is susceptible to aphids, caterpillars, leaf miners. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
Keep exploring plants
Shore knotweed is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Polygonum genus — compare its care with other Polygonum species on PlantoScan.
Polygonum is part of the Polygonaceae plant family — browse all Polygonaceae genera and species.
Shore knotweed thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Polygonum arenarium Waldst. & Kit., family Polygonaceae (first published in Descr. Icon. Pl. Hung. 1: 69 (1802)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Shore knotweed, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
Identify Plants Like the
Shore knotweed Instantly
Scan any plant with your phone camera and get instant ID, care tips, water and fertilizer reminders, and health checks — all in one app.
Free
to download
iOS & Android
platforms
Light & dark
mode
100,000+
species