Management of verges

Sustainable Harwell supports measures that will increase the biodiversity of our verges

The UK is one of the most nature-depleted countries in the world. The UK has lost almost half of its natural biodiversity. Many of the practises that we undertake in our everyday management of the environment contribute to this decline. At a local level one of the things that will help to reduce this is if we can increase biodiversity in some of our local managed areas, such as grass verges.

Many grass verges have little biodiversity. They have nutrient rich soil, which favours just a few species. Frequent grass cutting also reduces the opportunities for other species to grow.

We support less frequent grass cutting with removal of the cut vegetation. Over time, this will reduce the dominance of grass by lowering the nutrient status of the soil and allowing other species to establish. Over time, the amount of grass and the rate at which it grows will reduce. Verges will support more wild flowers, insects and other life.

Verges often form a boundary between hard engineered areas and pedestrian areas, giving some semblance of distance from traffic. However, it is important that safety considerations for visibility at junctions is also considered.

In an ideal scenario, we would have a wide range of vegetation in our verges, increasing biodiversity, and the grass would not grow so high that it obstructs visibility at junctions.

Obtaining the ideal state will require cutting of the verges with the cuttings removed, so that the nutrients in them do not go back into the soil when the cut vegetation rots. Cutting in Spring and around early August should be sufficient to meet current needs and lead to longer term improvements. There may be some junctions where extra cutting of a small area is needed to ensure good visibility.

Wherever new planting occurs, it will be important to limit the depth of topsoil to the minimum required to allow diverse species to establish. Any seeding should be dominated by local native species.

Recommendations

• Grass cutting on verges should take place no more than twice a year, except around junctions where more frequent cutting may be needed to allow good visibility.
• Vegetation should be removed whenever it is cut and this should be composted in a suitable local facility
• For any new work, no more than 5 cm of topsoil should be provided and this should be seed with a mix than includes local, native wildflower species.

More information on biodiversity and managing grass verges:

• Presentation to Sustainable Harwell on biodiversity by Alison Futter of the Environment Agency
• Amenity grassland and Road Verges – Doing More with Less
• Changing the way that we manage grass – presentation by Phil Sterling for the Environment Agency Thames Biodiversity Expo
• Plantlife – Transforming Britain’s Road Verges, which includes:
  • Managing Road Verges. A downloadable guide on creating and managing species-rich grassland of road verges
  • The Good Verge Guide. Downloadable guide to good verge maintenance