How to Control Thistle
Thistles are among the most reviled but easily recognisable of weeds. They can easily invade lawns, grassland & paddocks. Many will stand up proudly and most people know the pain of touching or standing on the prickly leaves synonymous with thistle weed.
What types of Thistle are found in the UK?
There are approximately 14 different species of thistle weed in the UK alone. The best-known umoung these include Creeping thistle (Cirsium arvense), Spear thistle (Cirsium vulgare) & Marsh thistle. Scotch thistle (Onopordum acanthium), sow thistle (Sonchus spp.) and Milk thistle (Silybum) are less common but visually retain a lot of the same characteristics.
Know your thistles? - Milk, Sow, Spear, Scotch, Creeping Thistle
Areas in need of Thistle Weed Control
Grassland areas, road verges and uncultivated ground are all prime spots for thistle growth. Thistles have developed their spiky leaves as a defence mechanism against grazing herbivores and they can quickly swamp a grazing paddock or lawn – out-competing grass and reducing available forage.
- Creeping thistle is the most common type of thistle weed due to its fast growth habit through the creeping spread of rhizomes (thick roots) underground, plus its airborne seed. The rhizomes are very brittle and can regenerate new plants from the smallest piece.
- Spear thistles have a single main fleshy taproot and spread via seed or division.
- Marsh thistles are enormous flattened plants that prefer… marshes! Any area which is poorly drained, with wet soils is ideal. You'll often find these thistles alongside soft rushes or in this type of environment.
Thistles will produce a variety of different coloured flowers – mostly purple to mauve and even yellow. The flower heads then become fluffy seeds which are adapted to air dispersal.
Thistle Weed Control Treatment
Digging/ pulling out thistle weeds can work for new paddocks by decreasing the numbers in a field. However, soft soils after rain are required to complete this and there is still the risk of leaving fragile root fragments behind to re-grow.
Did you know: Thistles are edible and have associated health benefits – especially for the liver but for most people afflicted they will need a reliable, Thistle control treatment.
What is the best weed killer for Thistles?
Glyphosate, such as:
These will have a good effect on young thistle seedlings but it is unsuitable for paddock situations where a selective herbicide is much preferred.
Selective herbicides are safe for grass. Their use can be in knapsacks (backpacks) or through a tractor mounted sprayer with boom arms. They have a wide m2 coverage per bottle which means they are also economical.
The best selective Thistle weed killers are: