Craven Lodge Residential and Offices
What was done
Callum Bain-Mackay of Grant Horticulture approached Green-tech for suggestions on the best way to get the optimal rooting volume for the tree pits, within the tight space constraints of the property. The original drawing from landscape architects Smeeden Foreman showed three trees, but it was decided that the length of the frontage could stand four.
The original thought was to use Green-tech’s sandwich-construction TreeRaft®, but the lack of space, made this unviable. So, Green-tech suggested the new TreeParker® Urban Tree Pit System, which would involve less digging out laterally of the existing made ground.
The initial plan was for separate tree pits for each tree, but on looking at the landscape drawing, Green-tech suggested one long trench. This offered two advantages over individual tree pits, especially as there were now four instead of the original three. Firstly, trees are quite happy to share space, so if we can provide them with one larger pit to share, the roots can borrow space from the other trees, in effect gaining more rooting volume. Secondly, by only excavating one trench, you can save time and labour costs over four individual pits.
The new TreeParker® system comprises rigid, modular units made from reinforced, recycled polypropylene. These units do a vital job in enabling the ground above a tree pit to be trafficked, supporting the paving above (up to 56t/m2), whilst at the same time protecting the soil below from compaction. This means that rather than having to use a fast draining and low organic structural tree soil, we can use our specially blended, GreenTree GeoCell topsoil, that is both friable and organic, ideal for successful tree establishment.
The TreeParker® units, although highly rigid, still provide 95% of their volume for rooting space. The heavy-duty, reinforced legs are available in various heights from the factory; 400, 600, 800mm and 1, 1.2, 1.5m. This gives a previously unheard-of flexibility with depth options. It also enables the units, by having legs rather than side walls, to easily straddle, or work around service pipes and lines.
This was the first time that Callum and his team had installed the system, and although TreeParker® has been used in high-profile projects throughout mainland Europe for several years, Grant Horticulture are the first company in the UK to install the system with Green-tech since its launch in March at Future Build. With this in mind, Green-tech was on hand to advise on the installation process, and even get hands on helping!
Callum, Grant Horticulture’s Lead Designer, and the team were very impressed with the speed and ease with which the units went in. Even when several unexpected service pipes were discovered running through the trench this didn’t pose a problem; the individual support legs of the units simply straddled the pipes, providing an easy workaround. The adjustability of the units is further enhanced by being able to be linked directly, or with 50 or 75mm spacers, or even stand alone.
Green-tech also supplied 40 tonnes of GeoCell topsoil and GreenTree subsoil direct from the soil bays at GT HQ, along with Mona Relief irrigation pipes and tree anchors.