Scientific Name: Cirsium palustre
Other names: European Swamp Thistle, European Marsh Thistle
A biennial which germinates in the autumn and over-winters as a basal rosette of spiney leaves. The following year upright stems can reach 1.2m in height and are branched with sharp spines up their length.
The leaves are deeply lobed with similar spines on the edges, but not on the surface.
The purple flowers appear from July to September, attracting bees, butterflies and flies. After pollination the mature seeds are dispersed on fluffy carriers.
The rosettes can be dug up and providing the crown is removed the tap-root will not regrow. Any plant which reaches the mature stage should be removed before the flowers lose their colour.
Selective weedkillers such as MCPA, 2,4-D and dicamba, are best used at the early rosette stage. Glyphosate can be used as a spot weeder.
See also Spear Thistle and Creeping Thistle
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Removal and Weed