
My visit to Chambord Symposium in June 2022 helped me to plan a tree-planting project in more details, in response to a civic plan to refurbish the retaining wall of my garden.
In December 2021, I inherited the house where I grew up in Aurillac. The property, owned by my family since the end of the 19th century, includes a listed garden. I intend to rejuvenate the garden, which has suffered decades of neglect.
Fruit trees used to grow in this south-facing walled garden. When I was a child, espaliered pear trees grew up against the big wall. I remember the wires guiding their branches, the lizards sunbathing next to them. I can still hear the sand falling from the crumbling mortar that joined the stones as the little reptiles ran after each other or swiftly climbed for safety behind the leaves when I tried to catch them. Vegetables were also grown in this garden, at an even earlier time.
As soon as I was made aware of plans to strengthen the retaining wall which separates my property from the adjacent premises of a public high school, I started to research how this refurbishment could be made compatible with my project to recreate a kitchen garden.
Observing and taking pictures
I examined the wall closely. Below are pictures I took mid-June to illustrate my wish to keep it breathing. This solution would give the best chance for the kitchen garden to thrive. It would also allow for the well-designed conservation of a listed place, giving it additional meaning in the context of renewed public interest in urban agriculture.






Additional elements collected at the Chambord Symposium
More than a hundred experts from six countries met at Chambord Castle in France on 23 June 20222 to discuss the conservation of historic kitchen gardens. Garden historians, landscape architects, owners of heritage properties, curators of public parks and gardens, head gardeners, experts of fruit trees and other participants such as myself met for the first time in person after two years of online conversations launched at the initiative of the UK’s Walled Kitchen Gardens Network3 and the French Association des Amis du Potager du Roi4. We visited three historic gardens the following day.

I took advantage of this symposium to search for information relevant to the rejuvenation of my garden. Here are my main findings.
Retaining wall
Specific mortars allow for walls to breathe. A technical expert and former curator of the fruit tree collections at the Potager du Roi told me that it was a good idea to keep dry stone at the basis of the wall and to use perspirant mortar above. He also said that adding particular components to the mortar helps grow fruit. He mentioned common practices such as adding crushed brick to capture the heat of the sun and charcoal which has antifungal properties. Further research into perspirant mortars would be required to choose the best option for the retaining wall in my garden.

The main function of a retaining wall is obviously to retain the mound behind. It should be solid enough not to collapse. We didn’t discuss this at the symposium as it was out of topic. Having said that, I came across a consolidated wall in Villandry which made me think about the big wall in my garden and the plan to make it safer. I have since read the safety diagnostic carried out ahead of this plan. Would a classical solution consisting in repointing joints with perspirant mortar and adding x-shaped crosses be satisfactory? Maybe not, even if the wall above my garden doesn’t look deformed, contrary to the one I saw at Villandry. More innovative solutions to secure this wall while keeping it breathing might have to be considered.

Espaliered trees
The former curator of the fruit tree collections at the Potager du Roi told me that my ancestors made the right choice in planting pear trees against our south-facing wall, as they require a lot of sun to thrive. Apple trees are better placed against walls that are less exposed to sunlight. My initial intention to follow in my ancestors’ footsteps and replant espaliered pear trees against the retaining wall has therefore been confirmed as the right thing to do.
The technical experts present at the Chambord symposium discussed the question of excellence in gardening practice and fruit tree training at length during our Friday’s garden visits. They used the fruit trees at hand to evidence and support their views in a concrete and practical way. I came to three conclusions for my garden.
Firstly, fruit trees are very specifically trained in prestigious historic kitchen gardens. They require a lot of care from expert gardeners, who not only apply their skills but also experiment with them to advance their already very elaborate techniques. What is put on show in these gardens is the excellence of their abilities, evidenced through trees strictly shaped which produce the best and loveliest fruit. My aim is different. I want to recreate a relatively low maintenance domestic kitchen garden that can be easily passed on to the next generation. Less precise shaping and more occasional care will make the trees look less groomed but will be more in line with what an amateur gardener can do.

Secondly, the experts pointed at some trees which were showing signs of weakness, highlighting why and what should be done in such cases. One of the reasons was that dwarf trees are more difficult to grow and require more care. I am now planning to plant more vigorous semi-dwarf trees as espaliers. In fact, they will resemble the old ones who grew there when I was a child, bigger and less trained than most of their prestigious historic kitchen gardens cousins.
Thirdly, I am going to follow the trend highlighted by the owner of a Belgian nursery which specialises in trained fruit trees. She mentioned that gardeners tend to leave more space between the espaliered trees and the walls now than before. I have enough space in my garden to do so, and this will contribute to optimising the conditions for the trees to flourish against the breathing wall.
In conclusion, there is room in my property for recreating a garden that will both testify of its past and show what we can do today to reduce our carbon footprint through domestic kitchen gardening. In this particular site, it might require to develop innovative solutions for the retaining wall to be both safe and breathing. I believe it is a challenge worth taking up which can only benefit all the partners who get involved in it.

To be continued.
References: (accessed 25 July 2022)
- https://lamaisonnature.ch/les-materiaux/mursperspirants/ (in French)
- http://europeangardens.eu/en/events/event/8761/ (scroll down to find the presentation of the event in English)
- https://www.walledgardens.net/about-us/
- http://www.amisdupotagerduroi.org (in French)
Intéressant; Paresseusement j’ai planté des poiriers ordinaires à 75 cm du mur; Cette solution dégradée est-elle un moindre mal ?
Bonjour Pierre,
75 cm, une distance supérieure à celle qu’on peut voir sur la photo des poiriers palissés de Villandry, me paraît bien pour des poiriers “ordinaires”. Qu’ordinaire signifie poirier de haute tige ou semi nain. Si vous les avez plantés récemment, il faut les arroser cet été, à raison je dirais de 20 à 40 litres d’eau en une fois tous les quinze jours. La recommandation du Urban Orchard Project est de 20 litres l’été pendant les trois premières années, mais le climat n’est pas le même et je tiendrais compte de l’exposition du mur. Il serait également bon de les tailler en février-mars pour les former, quelque soit la forme que vous souhaitez leur donner, afin d’obtenir à terme quatre ou cinq branches principales, que l’on appelle charpentières. Amitiés, Jean-Jacques