Easily recognizable due to its vase-shaped purple flowers with dandelion-like seeds, Canada thistle (Cirsium arvense) is a particularly aggressive invasive plant. Despite its name, Canada thistle ...

Spear thistle is another highly invasive plant which can easily outcompete other species of plants in the garden, so make sure to look for it. It can be recognised by its spiky leaves and purple ...

Sow thistle is commonly found in crops, gardens and waste areas. As with many members of the Asteraceae family ... The lobes in each leaf of prickly sow thistle do not tend to cut in so close to the ...