Dealing with weeds at clover establishment

See our advice on weeds and complying with spray legislation.  

Back to: Establishing clover

Establishment method

Here is an establishment method to help achieve weed-free grass/clover swards.

  • Maintain soil fertility to ensure that grass and clover can be competitive against weeds
  • Use glyphosate to kill off the old ley and any weeds
  • Sow into a clean seedbed to avoid competition from weed species during establishment
  • Sow the new ley without clover
  • Monitor the new ley and treat any weed problems before clover is introduced
  • Stitch or broadcast clover into the established sward from six weeks after weed control
  • Most weeds in reseeds can be controlled by management, e.g. grazing or topping, and do not need herbicides

If herbicides are needed after the clover is sown, use a clover-safe product. Only spray if clover plants are vigorous and well developed. It is recommended to use a weed wiper to treat target weed species only and to involve a BASIS-trained adviser. As part of the Sustainable Use Directive, anyone using sprays on farm must have an appropriate certificate and equipment (except knapsack sprayers) must be tested.

Complying with spray legislation at a glance

These measures apply to grassland weed killers:

  • Demonstrate that integrated pest management (IPM) is followed on your farm
  • The sprayer operator on your farm must hold a recognised certificate. Grandfather rights are no longer valid
  • All pesticide application equipment (except knapsack sprayers) must have a valid National Sprayer Testing Scheme (NSTS) certificate

These measures are a legal requirement for UK farmers through the UK’s Sustainable Use Regulations. Noncompliance could lead to prosecution and threaten your Single Farm Payment. They will also feature in Red Tractor standards.

Think water: Keep it clean

Many grassland weedkillers are detected in drinking water sources. Take extra care to protect water when filling and washing the sprayer and avoid over-spraying near ditches and streams.

Clover establishment in organic systems

In an organic situation, establish clover into stale seedbeds. Prepare the seedbed for planting a sufficient number of days before drilling to let the weed seeds germinate and emerge. When soil moisture allows germination, subsequent flaming, harrowing or drilling will eliminate many of the germinating weed seeds.

Useful links

Learn more about grassland reseeding

Read the Establishing and growing clover guide

If you would like to order a hard copy of the Establishing and growing clover guide, please contact or call 0247 799 0069.

The information in these web pages was sourced from Germinal, Grassland Development Centre (IBERS, University of Aberystwyth) and Charlie Morgan (GrassMaster Ltd).