Take steps to control thistles in grassland

28 Jun 2020

Now is the time to tackle thistles in grass leys. Fields filled with 10% thistles produce 10% less grass to feed to livestock, according to Corteva Agriscience’s Nicola Perry.

“As early grass growth has been poor in many parts, forage supply might not meet the demands of grazing cattle,” she says.

Translocated herbicide

“So spraying thistles with an effective translocated herbicide, specifically designed to kill the roots of the plants, will help to optimise grass growth for the rest of the season.”

The two most common and damaging thistles in the UK are creeping thistle and spear thistle. Both compete with grass for space, light, nutrients, and water.

Root systems

“They reduce the amount of grazing available and are unpalatable to stock,” adds Dr Perry.

She adds that spraying them with Thistlex, at a rate of one litre per hectare in between 200 litres and 400 litres of water, will give good control of creeping and spear thistles, as well as other weeds such as common nettle, fat hen and mayweed.

“The herbicide gets right down into their large vertical and horizontal root systems.

Active re-growth

“In mid-summer it may pay to top well-grown thistle plants and spray the active re-growth two to three weeks later.

“Animals must be taken out of the field when it is sprayed, but they can return seven days after treatment if there is no foliage of poisonous weeds, such as ragwort, present.”