Day 58 - Leaks

I had already established in conversation with my team that there existed in our chalk-pit a piped source of mains water which had lain neglected for many years. I asked our man to hunt it out and show me if it still worked. It took a bit of scrabbling in the undergrowth, but eventually he revealed a buried tap under the soil in a fairly inaccessible part of the steep banking, and with the application of heavy effort to the wrenches, succeeded in coaxing water from it. Relieved to have found this, I then dropped the bombshell on him. He would now be required to dig up the work he had just completed in order to set up an irrigation system. After all, if you are going to be growing water-demanding foliage plants in a dry chalk-pit, you have to give yourself some advantages over the elements. This was following tradition, not 'right plant, right place' à la Beth Chatto. Why? may be a question worth asking, although the soil improvement was changing the conditions already. There was no choice about the order of proceedings. however, as the leaky pipe I intended to use had to be installed six inches below the surface, so it couldn't have been laid first, before digging and manuring began, or it would simply have been dug up and through in the process of soil amelioration.

Anyway, with his customary doggedness, our man set about following my instructions and siting the pipe. The trouble with leaky pipe is that it operates well only if it is laid perfectly level, and it also only works at low pressures, and very slowly. Too high a pressure and all the water forces itself out at the start of the run and never reaches the far end of the system. You have seen the photographs. The beds rose and fell with no predictable pattern. He had to lay the pipe at roughly one metre spacings back and forth over the entire area, and then test it to see if he could persuade it to flow from the tap as far as the blanking cap at the other end over 200 metres away. It took ages and considerable patience, digging six-inch deep trenches, laying the pipe in them, turning on the water and seeing where the flow stopped, then making small adjustments to get the water running a little further. He placed canes below the pipe to guide it, and where adjustments had to be made, he would move the canes, rest the hose against the new position, turn on the tap and wait. Eventually the whole system worked. Then it was necessary to cover the pipe with soil, filling in the trenches. We tried to keep in mind where the run of irrigation went, because obviously, at six inches below the surface there was a real danger that when we came to plant the beds up, we would slice through it with our spades. Initially we planted with the pipes exposed to avoid this, but this was impossible with subsequent operations after the the layout was completed. My premonition was proved correct on numerous occasions, but being a Head Gardener with considerable foresight, I had prepared myself by purchasing plenty of jointing tubes for repair purposes. Tomorrow will be the day when I begin to show you how the plantings developed over time. Suffice it to say that the watering system helped to a certain extent with the establishment of the young plants, whilst at the same time satisfying one of the environmental demands I had placed on us - I was trying to put water directly at the roots, without wasting any to evaporation. Whether it worked as I had hoped or not is highly debatable. It may be a system which works on perfectly level nursery areas, where everything is predictable and the position of the tubing can be permanently marked. Not only did we keep digging it up and cutting through it, which messed with the levels required for consistent flow, but it also seemed that in our heavy but thin soil, the moisture never properly spread out to fill the area between the pipes. We could see strips a foot wide which showed us where the water was seeping out, but it never fully covered the whole metre between the serpentine layers of the system. A lot of work for dubious results. but it was better than nothing. In the process of installation it looked like this, in case my description hasn't clarified it enough -

Various other views show the extent of the work, and also how the feature fitted into the surrounding landscape, forming the most dramatic change of level withing the garden -

Tomorrow the plants will start to arrive.