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Japanese Knotweed, False Bamboo, Mexican Bamboo
Fallopia japonica 'Crimson Beauty'

Family: Polygonaceae
Genus: Fallopia (fal-OH-pee-uh) (Info)
Species: japonica (juh-PON-ih-kuh) (Info)
Cultivar: Crimson Beauty
Synonym:Polygonum cuspidatum
Synonym:Pleuropterus cuspidatus
Synonym:Polygonum cuspidatum var. compactum
Synonym:Polygonum zuccarinii
Synonym:Reynoutria japonica



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Flowers are fragrant

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)


24-36 in. (60-90 cm)


USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

Sun Exposure:

Sun to Partial Shade


Unknown - Tell us

Bloom Color:

Scarlet (Dark Red)

Bloom Time:

Late Summer/Early Fall


Grown for foliage




Other details:

Unknown - Tell us

Soil pH requirements:

Unknown - Tell us

Patent Information:

Unknown - Tell us

Propagation Methods:

By dividing the rootball

Seed Collecting:

Collect seedhead/pod when flowers fade; allow to dry


This plant has been said to grow in the following regions:

Pelham, Alabama

Glen Ellyn, Illinois

Newburgh, Indiana

Clinton, Mississippi

Stratham, New Hampshire

Gilbertsville, Pennsylvania

Millersville, Pennsylvania

Charleston, South Carolina

Bristol, Tennessee

Loudon, Tennessee

Murfreesboro, Tennessee

Primm Springs, Tennessee

Bridgewater, Virginia

Faber, Virginia

Newport, Virginia

Norfolk, Virginia

show all

Gardeners' Notes:


On May 17, 2010, Erica1171 from Newport, VA wrote:

It does not spread by seed in this part of the east coast (mountainous Virginia), but spread VERY easily when tiny bits of roots are moved (as in bulldozer work).

It is very hard to get rid of, too. VERY. 25% glycophosphate helps on cut stems. Applied on foliage, the plant laughs. Those little peices of roots keep expanding to bigger and bigger patches.


On Sep 27, 2009, dbelcher from Florence, SC (Zone 8a) wrote:

In South Carolina the Japanese Knotweed is listed on their Invasive Plant list as a Severe Threat.


On Aug 25, 2009, Kim_M from Hamburg, PA (Zone 6b) wrote:

This plant stays in it's place. But wherever the place is make sure it has a lot of room. It grows extremely fast. At first I thought it may be a bit invasive, but it isn't. Just a very fast strong aggressive grower.