Chambord was spectacularly transformed in 2017: the château has rediscovered its French-style gardens, restored to their 18th Century splendour. These gardens, which cover an area of six and a half hectares at the foot of the castle’s northern façade, contains more than 600 trees, 800 shrubs, 200 rose bushes, 15,250 border plants and even 18,874 m2 of lawns. This lightning project began in August 2916 and was completed five months later. It has been completely financed by an American philanthropist, Mr. Stephen A. Schwarzman, president and founder of the Blackstone Society. The company SIREV was responsible for the irrigation part of the project.
The gardens have been restored to their original state Originally commissioned by Louis XIV, with the design completed in 1734, these gardens have been in existence for more than two centuries. Having fallen gradually into disuse, the area had become nothing more than a patchy lawn by 1970, remaining in this transitional state for 40 years. The restoration of these gardens required a preliminary study of the available historic sources of water to support the project. This in turn led to the researchers not only examining the archives and engravings, but also looking for relevant information made available from the existing archaeological sites, geophysical surveys or more thorough excavation. Thanks to these investigations, it has become possible to recreate an outstanding reconstruction of the French-style gardens, just as they were in the mid-eighteenth century. The château and gardens are organized according to a principle of quadripartition, with the building being the base element (see p.51) and the other three “squares” forming the gardens. The parterres, made up of lawns, flowerbeds, arrangements and quincunxes of trees or bushes, were restored to their original form and dimensions. The original 18th Century location of the paths and side alleys was reproduced. Only the plant species had to be adapted to the current climate and changing soil and plant health conditions. For example, the horse chestnut and boxwood trees, formerly planted in the garden, are now affected by disease so they have been replaced by similar varieties to preserve the aesthetic aspect. SPRINKLER INSTALLATION FOR THE FRENCH-STYLE GARDENS Along with Jean-François Malgogne from the company Sirev, on a hot summer day in June, we walked towards the first square section of the French-style garden, situated in front of the château’s northern façade. Two magnificent lawns with embroidery-type patterns, which we had designed, unfuried superbly before our eyes. They are surrounded by flower beds. “For these flowerbeds, Mr. Jourd’heuil selected plants that were in keeping with the historical reconstruction of the gardens, but certain species had to be adapted to the current climate and phytosanitary conditions,” explained Mr. Malgogne. We were able to observe coneshaped yew trees, which must be two to three metres in height. This is the same species that was present in the gardens of Chambord in the 18th century. On the other hand, the boxwood trees, which, nowadays, are susceptible to diseases, have been replaced by the small-leaved Japanese spindle. And annual plants have been replaced by more resistant perennial species, which have a life span of several years and require little attention to thrive. Finally, between the different square sections that make up the French-style gardens, lime trees have been planted along the single and double garden paths. Originally, the species planted was the horse chestnut but these have been discarded because they became affected by a parasite that could only be controlled with the use of pesticides, which is against the estate’s environmental policy. For the watering of the whole complex, three parallel irrigation systems have been installed: • Rain Bird 8500 long-range stainless-steel sprinklers for irrigating lawns because there are two outside rows of sprinklers and one central row. • One self-regulating drip irrigation system for the flower beds, laid out in such a way to obtain a uniform density of 6 drippers per m2. • RWS bubblers for irrigating the trees, laid out in such a way that there are 3 bubblers buried next to each tree. The macro-drippers are installed around the tree at the time of planting. We could see the solenoid valve boxes between the paths, covered with gravel. They are hidden from the view of the visitors at the request of the Monuments Historiques National Heritage commission. The installation is 100% Rain Bird, because the landscape architect only wanted to use one single manufacturer offering a complete range of equipment, which is not too sophisticated and of good quality. Everything is managed by a Rain Bird ESP LXD controller and an IQ Cloud central control system, a nonsequential decoder system controlled by a flow meter with hosted software. “The software has not yet been installed, but the people in charge of maintaining the site have access to it via their mobile phone, tablet or computer”, explained Mr. Malgogne. “As far as site maintenance is concerned, an employee from the company Espaces Verts Richard works on site every day and we manage the working tool”, explained Mr. Malgogne. The IQ Cloud software provides the local meteorological data and produces a summary. The gardener sends an email to the company SIREV every day. “The tool is sophisticated but it is always the gardener who makes the final decision”, explained Mr. Malgogne. The first year is important because the different species have only recently been planted on very poor soil. It should not be forgotten that the Chambord gardens are artificial. On the day of our visit, the weather was very hot, 39° in the shade, and Mr. Malgogne gave the instruction to increase the amounts of irrigation water applied: “We need to increase the dosage from 4 to 8 mm this week”, he explained. The site managers are very vigilant because they don’t want to lose any of the plants. We then headed for the second square section, planted with 400 cherry trees (double flowering sweet cherries), composed of four square copses and planted on a grass underlay. These trees are irrigated with spray heads equipped with MP Rotator nozzles, which have an excellent throw radius and cover and they optimise water consumption. The pumping station must also be used for the English-style garden Finally, we went to the pumping station located near the flower beds, just above the canal, which acts as a permanent reservoir for the untreated water used for irrigating the gardens. The service room that houses the pumping station has, up to now, been used by the firemen for fire-fighting purposes. They will be changing over to dry risers /dry standpipes in September so it will be possible to recover the existing pumps and tanks and use them for irrigating the gardens. The controller and electrical cabinet are located outside. We then went down to the service/ control room, which houses the pumping station. That is where we could see the tanks that store 500 m3 of water as a buffer volume, representing an average of 5 days irrigation; a primary pump takes water from the canal and fills the tanks. The water is then filtered and redirected outside, to the irrigation network. A software programme has been developed internally to manage the pumping station remotely. It allows the pumps to start up, provides the flow/pressure curves and water level and gives an indication of electric power consumption. This pumping station must eventually allow for the irrigation of the English-style garden, which is located close to the entrance of the château. This garden was created by the same landscape architect Thierry Jourd’heuil just before creating the French-style gardens, with no irrigation facility, in accordance with the estate’s environmental policy. However, the hot weather of this spring is changing the mind of those people in charge of the estate because welcoming the visitors with a scorched lawn does not produce the best effect. Furthermore, they do not want to take the risk of letting these plants of quality shrivel up and die.