Spot-treating large perennial weeds such as brambles, gorse and broom in summer will catch them at the right time before they start dying back for winter, giving the best results according to Dr Nicola Perry, weed biology specialist for Corteva Agriscience.
“These tough, woody weeds typically grow around the edges of fields, under fence lines and in gateways, restricting access, limiting grass growth and creating problems where prickly brambles can catch in sheep’s’ wool,” says Dr Perry.
“Grazon Pro will give good control and is one of few products approved for use with a knapsack sprayer or hand-held lance in established grass. This means it is ideal for treating patches of difficult or isolated weeds, for example on steep ground. Bramble bushes, gorse or broom do not need cutting back before treatment but must be sprayed thoroughly, wetting all the foliage but avoiding any run-off.”
Brambles are widespread throughout the UK and have long, thorny arching stems bearing blackberry fruits. Gorse can grow to a height of three metres with a mature infestation producing up to 6 million seeds per hectare per year. Left untreated, encroachment across fields is common. Broom, which looks similar to gorse but without the spines, can be particularly invasive in poorer pastures.
Grazon Pro contains clopyralid and triclopyr and is a professional use product, so can only be applied by people holding a PA1 and PA6 certificate of competence in the Safe Use of Pesticides, issued by the National Proficiency Test Council. They should also wear suitable Personal Protective Equipment (PPE) including a face shield, gloves, coveralls and rubber boots during preparation, spraying and the cleaning process.
Use 60ml Grazon Pro in 10 litres of water in each knapsack. After application, livestock should be excluded for at least seven days and until the foliage of any poisonous weeds such as ragwort has died and become unpalatable. Grazon Pro is very safe to grass and is rainfast in as little as two hours.