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Fallopia japonica (Japanese knotweed)

Intermediate
skill rating
3 hours care
per year
4m
Max height
1m
Max spread
5-10 years
To maturity

Plant details

Botanical name

Fallopia japonica

Other names

Japanese knotweed, Giant knotweed, Polygonum cuspidatum, Polygonum reynoutria, Reynoutria japonica, False bamboo, Mexican bamboo, Himalayan fleece vine, Monkeyweed, Monkey fungus, Hancock's curse, American bamboo

Genus

Fallopia Fallopia

Species

F. japonica - F. japonica is a vigorous, upright to climbing perennial with hollow stems bearing broadly ovate to heart-shaped, mid-green leaves and erect racemes of small, cream or white flowers in late summer and early autumn.


Fallopia japonica is: Deciduous

Habit

Climbing, Spreading

Flower

White in Summer

Foliage

Green in Summer

How to care

Watch out for

General care

Pruning

Dig out small clumps. Cut plants down every 2-3 weeks over several years to weaken. Alternatively, cover the affected ground with sheet mulch but stems can pierce most materials. Herbicides can be applied but this does not produce long-term results.


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Where to grow

Fallopia japonica (Japanese knotweed) will reach a height of 4m and a spread of 1m after 5-10 years.

Cultivation

An highly invasive species in all introduced areas. Planting or causing it grow in the wild is prohibited. Extremely difficult to eradicate.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid, Alkaline, Neutral

Light

Partial Shade, Full Sun

Aspect

North, South, East, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

Companion plants

We do not currently have companion plants added for this plant.

Botanical name

Fallopia japonica

Other names

Japanese knotweed, Giant knotweed, Polygonum cuspidatum, Polygonum reynoutria, Reynoutria japonica, False bamboo, Mexican bamboo, Himalayan fleece vine, Monkeyweed, Monkey fungus, Hancock's curse, American bamboo

Genus

Fallopia Fallopia

Species

F. japonica - F. japonica is a vigorous, upright to climbing perennial with hollow stems bearing broadly ovate to heart-shaped, mid-green leaves and erect racemes of small, cream or white flowers in late summer and early autumn.

Foliage

Deciduous

Habit

Climbing, Spreading


Colour

Flower

White in Summer

Foliage

Green in Summer

General care

Pruning

Dig out small clumps. Cut plants down every 2-3 weeks over several years to weaken. Alternatively, cover the affected ground with sheet mulch but stems can pierce most materials. Herbicides can be applied but this does not produce long-term results.


Monthly care advice


Where to grow

Fallopia japonica (Japanese knotweed) will reach a height of 4m and a spread of 1m after 5-10 years.

Cultivation

An highly invasive species in all introduced areas. Planting or causing it grow in the wild is prohibited. Extremely difficult to eradicate.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Acid, Alkaline, Neutral

Light

Partial Shade, Full Sun

Aspect

North, South, East, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 8, Zone 7, Zone 6, Zone 5, Zone 4

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Fallopia japonica (Japanese knotweed)

Fallopia japonica (Japanese knotweed)

Fallopia japonica (Japanese knotweed)

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This plant likes... Garden match
Soil types: Chalky, Clay, Loamy, Sandy (will tolerate most soil types) Tell us...
Soil drainage: Moist but well-drained, Well-drained Tell us...
Soil pH: Acid, Alkaline, Neutral Tell us...
Light: Partial Shade, Full Sun Tell us...
Aspect: North, South, East, West Tell us...
Exposure: Exposed, Sheltered Tell us...
Hardiness: Hardy (H4) Tell us...

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how can I prevent this plant from spreading further? It's terrible

how can I prevent this plant from spreading further? It's terrible read more

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