Knotweed
Persicaria spp.
Also known as
Smartweed
Persicaria glabra in Narshapur forest, AP W IMG 1109 by J.M.Garg (CC BY-SA 4.0)
Full Sun
Easy care
Moderate watering
Frost Hardy
H7-H4
RHS hardiness
-20°C
Minimum temperature
Expected size
Height | Spread | |
---|---|---|
1.2m | Max | 1.2m |
25cm | Min | 60cm |
Flowering
-
spring
-
summer
-
autumn
-
winter
More images of Knotweed
Knotweed Overview
Persicaria - known also as Knotweed or Smartweed - is a genus of mainly annual, semi-evergreen, evergreen or herbaceous perennials that originate from a wide range of habitats worldwide. Knotweeds typically have simple leaves and long-lasting spikes of small bell-like - usually pink or white - flowers. Some species are cultivated as creeping ground cover and some for their autumn leaf colour. Some species however, can become invasive. Persicarias like moist soil and are happy in full sun or partial shade. Popular in borders and rock gardens, there is a species for almost every garden situation.
Common problems with Knotweed
How to propagate Knotweed
Division
Seed
Cuttings
Cuttings of non-flowering shoots in mid-summer.
Special features of Knotweed
Attractive flowers
Autumn colour
Ground cover
Other uses of Knotweed
Grown for their foliage.
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Damp, wet locations are perfect for these perennial plants.
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