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Japanese Knotweed, False Bamboo, Mexican Bamboo 'Devon Cream'

Fallopia japonica

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




Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


24-36 in. (60-90 cm)

36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 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)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

Sun Exposure:

Sun to Partial Shade

Light Shade


Unknown - Tell us

Bloom Color:

White/Near White

Bloom Time:

Late Spring/Early Summer

Mid Summer

Late Summer/Early Fall


Grown for foliage



Good Fall Color

Other details:

May be a noxious weed or invasive

Soil pH requirements:

Unknown - Tell us

Patent Information:

Unknown - Tell us

Propagation Methods:

Unknown - Tell us

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed


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


Ben Lomond, California

Boulder Creek, California

Calistoga, California

Clayton, California

Fairfield, California

Mount Prospect, Illinois

Saint Paul, Minnesota

Media, Pennsylvania

Wilkes Barre, Pennsylvania

show all

Gardeners' Notes:


On Apr 23, 2016, coriaceous from ROSLINDALE, MA wrote:

The sale, purchase, planting, and cultivation of all forms of this species are illegal in my state and seven others, because of the damage it does to natural areas.

I maintain a garden with a dwarf variegated form of this species---it may well be this cultivar. Both neighbors have the wild-type on the adjacent edges of their properties. I'm fairly sure it's spread there by seed from the variegated form.


On Jul 10, 2004, Nordlund from Madison, WI wrote:

I've grown three of these plants in Southern Wisconsin for 4 years, two in partial shade and one in sun. The plant in full sun is larger at about 3 feet tall and three feet wide. In partial shade, the plants are closer to 2 feet tall and less dense.

They have not been invasive in ordinary garden soil. Occasionally, perhaps three times in as many years, a shoot has emerged 6 inches from the original plant.