Common Name: Japanese knotweed
Type: Herbaceous perennial
Family: Polygonaceae
Native Range: Eastern Asia
Zone: 5 to 9
Height: 1.00 to 2.00 feet
Spread: 1.00 to 2.00 feet
Bloom Time: June to July
Bloom Description: Pink
Sun: Full sun to part shade
Water: Medium
Maintenance: Medium
Suggested Use: Ground Cover, Naturalize
Flower: Showy
Leaf: Good Fall
Attracts: Birds
Tolerate: Deer, Drought
Culture
Easily grown in average, medium, well-drained soil in full sun to part shade. Best flowering in full sun, but appreciates light shade in drier soils and in hot, humid conditions. Is invasive, but less so than the species.
Noteworthy Characteristics
Fallopia japonica var. compacta, commonly called Japanese knotweed is clumping perennial which spreads by rhizomes and is often grown as a ground cover. It typically grows only 1-2' tall. Features loose clusters of pale pink flowers in summer which mature to red and are followed by red seeds. Heart-shaped (to 2" long), red-veined, green leaves turn red in fall. Arching stems have sheathed and swollen nodes.
Genus name honors Gabriele Fallopi (1523-1562), Italian anatomist, professor of anatomy at Pisa and Padua after whom the Fallopian tube was named.
Specific epithet means of Japan.
Problems
No serious insect or disease problems.
Uses
Less invasive than the speices but still not recommended.