Protecting Roadside Verges of Ecological Importance
Monday, 16 June 2014
As the annual verge cutting season is under way highways teams across Hampshire are taking extra care to manage Hampshire's 226 Roadside Verges of Ecological Importance.
Good visibility is vital for motorists and other road users and so it is important to trim back verges to maintain clear lines of sight.
Verge cutting is also timed to manage designated Road Verges of Ecological Importance which have identified rare flower species. These verges are cut either early in the season during April, to reduce invasive plants such as thistles or vigorous grasses that may have taken hold over the winter, or in late September so that rare species have had time to flower and set seed for the next year.
Regular mowing mimics grazing by animals, or the taking of hay crops, which traditionally maintained species-rich grassland in the past. Too little mowing can promote grass growth at the expense of the flowering herbaceous species - most of which are perennial and will keep coming back. Some of the chalk grassland verges, on the Alresford by-pass for example, thrive on regular cutting because it maintains the short, cropped, species rich downland habitat once maintained by sheep.
Verge cutting is undertaken in both rural and urban areas. In general rural grass verges are defined as areas with speed limits of 40mph and above and are cut by the county council's highways term contractor Amey who use local sub contractors. Urban grass verges tend to be on roads with a speed limit of 30mph or lower and are cut by the 11 district councils in Hampshire on behalf of the County Council.
Rural grass cutting is carried out twice a year, with the first cut normally taking place in May and June. The second cuts start in early September and should be completed by the middle of October.
Work on most of the rural road verges consists of a one metre wide cut but at junctions, bends and in front of traffic signs the grass is cut back further to ensure good visibility for motorists. In addition, the remaining areas of verge are cut once every three years in rotation, in order to prevent them from becoming overgrown.
Specialist rare plants are earmarked for particular mowing regimes that avoid their main flowering season. For example several verges around Four Marks support the rare Violet helleborine which flowers late and should therefore not be cut until late October.
In central Hampshire, particularly between Winchester and Basingstoke, Dark Mullein grows in some verges. This is the food plant for the rare Striped Lychnis moth - only found in southern central England. These verges receive an April cut only as the caterpillars feed on the plant until September.
The Hampshire Biodiversity Information Centre (HBIC) monitor these special road verges on a rolling programme to ensure their interest is maintained. Some verges are deselected if rare flowers or species no longer inhabit them and new verges are selected if they are found to support rare species or habitats which were previously not know about. HBIC also actively screens all proposed road works on a weekly basis to alert the authorities or utility companies to minimise important verges being damaged from digging or storage of machinery/materials.
Councillor Seán Woodward, Executive Member for Economy, Transport and Environment at Hampshire County Council said: "Good visibility for all road users is critical and so it is important to make sure that our verges are trimmed. Hampshire has almost 6,000 miles of road and over 2,000 miles of them are covered by the rural grass cutting programme and the same if not more in urban areas. We balance this with the need to ensure that plant and wildlife habitats of special interest are protected and, with sensible timing, managed verge cutting can support wildflowers and rare species."
"This is a very busy time for our grass cutting contractors so please be patient if you get stuck behind a slow moving vehicle. We always try to keep any inconvenience to road users to a minimum but the work to keep our roads and verges in good condition is in everyone's interest."