We are committed to maintaining Clapham Common. Following the event we are working with Lambeth Landscapes and specialist agronomists on the reparations works as below.
Around 10 tonnes of imported topsoil will be used to fill in of any ruts or depressions. This will consist ideally of a sandy loam to the current BS standard. Surplus soil will be spread evenly over more level areas subject to thinning ground cover.
When ground conditions over the site are sufficiently firm, the verti-drain treatment will commence immediately. A small fixture fitted to a smaller tractor with grass tyres may be used initially, but the aim will be to achieve as substantial a compaction relief effect as possible. This means using as large a combination of verti-drain and tractor as the ground conditions will allow. If the combination is producing undue damage to the surface, the operation should be delayed until ground conditions are suitable. All areas of the site should be treated.
Over-seeding will commence as soon as the verti-drain operation has completed, using a 100% dwarf perennial ryegrass seed mix. A standard sowing rate of 35 g/m2 will be adopted over all areas obviously affected by the event. Areas where almost all ground cover has been lost will require a rate of around 50 g / m2. If a standard pass delivers 18 g / m2, some areas may be treated to 1, 2 or 3 passes depending on the severity of the ground cover loss. A disc seeder will be used. Smaller versions (say 1.2 m width) will be more versatile in negotiating the varying shapes and sizes of the treatment areas. The discs should deposit the seed around 8 mm below the surface.
Fertiliser application will be suitable around early March when it would be appropriate to apply a granular fertiliser of analysis 14 : 6 : 6 or similar at a rate of 35 g / m2.