The bioclimatic greenhouse

The Ivory Foundation has funded the construction of a bioclimatic greenhouse in the Grand Potager garden at Domaine de Lauris. Also known as a “passive solar greenhouse”, the bioclimatic greenhouse is part of an environmental and sustainable approach.

Its components and configuration insulate it to reduce heat loss. So it stores solar energy during the day and releases it at night or during cloudy spells. At night in winter, for example, the difference in temperature between inside and outside can be as much as 20° in some parts of the greenhouse.

The natural convection of the air flows lets the outside air in through vents along the edges of the greenhouse at the bottom and lets it escape along the length of the ridge at the highest point of the greenhouse, preventing overheating. All this is automated using thermal jacks that consume no energy.

The good insulation of the walls towards the outside and the presence of an air space in the polycarbonate sheets of the roof keep the heat in the greenhouse.

The south wall is transparent (in this case made of glass) so that the sun’s rays can penetrate the greenhouse. For optimum sunlight and maximum solar energy, the inclination of this wall is 65° to the horizontal, i.e. almost perpendicular to the rays of the winter sun.

A rainwater collection and storage system is used to irrigate the plants. As well as not wasting this natural resource, which is de facto captured by the roof, rainwater is the best water for irrigation (ph neutral, not mineralised, no pollutants, no chlorine, no germs…). It is also well suited to organic treatments, such as spraying purins and biodynamics.

Dynamic rainwater collection and storage provides thermal storage by inertia of the day’s heat and releases it at night in cold periods. The advantage of this technique is that it adapts to the seasons. In hot weather, when overheating must be avoided, the water stored during the winter is gradually used and/or emptied, so the containers no longer heat the greenhouse in summer.

Blackout blinds let in the winter rays that heat the water storage during the day, while in summer they shade it. This gives better temperature control.

The advantages of the bioclimatic greenhouse :

  • The production period is extended. (Approximately 1 month earlier).
  • Some vegetables can be grown in winter.
  • Aromatic plants, vegetables and flowers are protected from frost.
  • It complies with the organic farming charter, which regulates greenhouse heating.

The use of the campagnole

In this video, Émile takes us through the steps involved in preparing mounds for cultivation. First step: loosen the soil with the Campagnole! The Campagnole is a particularly interesting tool when it comes to permaculture in the garden. Invented by Vincent Legris, in collaboration with the Bec Hellouin farm, it is an “improved grelinette”, but with 2 wheels to make it easier to move around. It has two rows of tines, one of which penetrates the soil, while the second remains on the surface to break up clods and keep the soil on the cultivation mound. Easy to use, it is highly effective for loosening and aerating a cultivation area, while respecting the soil’s life to the maximum. Next step: the beds are levelled and covered with compost!

The Ivory Foundation has also financed the purchase of a campagnole to maintain several of the gardens it supports, such as those in Lesotho and the Jardin des Savoir-Faire.