Weeds Act 1959

The Broad Leaved Dock is a resilient and common perennial plant found in grasslands throughout the United Kingdom. Unaffected by regular climatic variations and all but the most acidic soils, the Broad Leaved Dock can produce around 60,000 seeds a year and flowers from June to October. The seeds can survive for up to 50 years in soil due to a 'chemical that inhibits microbial decay'.[3]

The Curled Dock is found mostly in meadowland, wasteland, sand dunes, and dry soils. The Curled Dock can be annual, biennial, or perennial, and can produce 3000 to 4000 seeds per plant.[4] Although said to contribute to animal wellbeing by providing nutrients which would otherwise be absent, it also contains oxalic acid which could be damaging to stock.[5]

The Creeping Thistle is a common resilient perennial plant found in grasslands throughout the United Kingdom. Characterised by spined lobed leaves, it stands up to one metre high and blooms with light purple flowers between July and September. Its root system is very deep, extending up to three metres underground and six metres sideways;[6] as such, it is very hard to remove from an affected area. It competes fiercely with other plants or crops and can release a natural biocide into the soil to inhibit growth of other species.

The Common Ragwort is a biennial yellow angiosperm which can grow to 30–100 cm high. A ragwort plant can produce around 30,000 to 120,000 seeds but as this is a native plant in the UK these would on average only create one new plant. It can be toxic to livestock if it is contained in hay and it contains several kinds of Pyrrolizidine alkaloid which can, if the dose is high enough, cause liver damage.

The Spear Thistle is an annual or biennial plant which forms dark purple or reddish flowers above dark green spiked leaves. A plant found in pastoral land and along roads, it is easily spread by vehicles as they pass by.[7]