Lesser Knotweed flowers
(Photo courtesy of NetPS Plant Finder)
Height: 24 inches
Spacing: 20 inches
Hardiness Zone: 4a
Other Names: Bellflower Smartweed, Polygonum campanulatum
Lesser Knotweed features airy spikes of shell pink flowers rising above the foliage from early to late summer. The flowers are excellent for cutting. Its textured pointy leaves remain green in colour throughout the season. The fruit is not ornamentally significant.
Lesser Knotweed is an herbaceous perennial with a mounded form. Its medium texture blends into the garden, but can always be balanced by a couple of finer or coarser plants for an effective composition.
This plant will require occasional maintenance and upkeep, and is best cleaned up in early spring before it resumes active growth for the season. Gardeners should be aware of the following characteristic(s) that may warrant special consideration;
Lesser Knotweed is recommended for the following landscape applications;
- Mass Planting
- General Garden Use
Planting & Growing
Lesser Knotweed will grow to be about 24 inches tall at maturity, with a spread of 24 inches. When grown in masses or used as a bedding plant, individual plants should be spaced approximately 20 inches apart. It grows at a fast rate, and under ideal conditions can be expected to live for approximately 10 years.
This plant performs well in both full sun and full shade. It prefers to grow in average to moist conditions, and shouldn't be allowed to dry out. It is not particular as to soil type or pH. It is highly tolerant of urban pollution and will even thrive in inner city environments. This species is not originally from North America. It can be propagated by division.