The Peripheral Road projectLeave a Comment
It was a difficult January for planting work on the Peripheral Road project near Peterborough, and because the area where we were working is on clay soil there were several parts of the site where the conditions made it quite challenging for us. Even so, in general we did not seem to be hit as badly as most people were by the bad weather.
Last time we explained some bare root autumn preparation which stood us in good stead; in fact this has been evident by the complete take of plants as they are breaking bud.
Gunpowder Park, Lee Valley, Enfield – All indigenous planting was done directly into subsoil on this site, which was formerly the Royal Ordnance Site where World War Two armaments, including the Bouncing Bomb, were made. It was a heavily polluted 36-hectare site, all capped with 1 metre deep of clay.
This site was unique in that all the planting mounds were subsoil, so we double dug the mound with “a 360 digger” to 1 metre deep adding Biogram (a pelleted human sewage by-product). We then worked this in to 400m with a heavy duty spading machine, the type used to regenerate old coal tips etc. Plant roots were inoculated with fungal compost, and the amazing thing was that plant losses were less and growth rate was better than on a normal topsoil site!
The Peripheral Road Project: We had to get this work done while lane closures were in place, which meant that we had to plant in almost impossible conditions, i.e.sticky newly-laid ‘unripped’ and unmanageable clay topsoil, and in a very limited time. The way round the problem was to add compost to all the planting stations, which stopped them from freezing.
These pits could then be planted easily, even on frosty days. By notching planting through compost, we completed the project according to the original timescale. It meant that we could work when most contractors were stopped by the bad weather. Although this wet clay site was like concrete in the recent dry weather, the plants are all in leaf and looking well.
Another planting method we used for bare root planting on this site was to introduce a mix of 50:50 topsoil and subsoil in the planting pits on sloped areas. We then dug them over with compost. It will be interesting to see how this blue clay subsoil mixed with topsoil performs.