In France Bouillie Bordelaise is universally used as a preventive measure against fungal and bacterial diseases. It limits the settling of cankers, moniliose (fungicide causing rotting of fruit), leaf curl, scab and mildew.
Bouillie Bordelaise is composed of copper sulphate and hydrated lime. Copper, a trace element, naturally present in small doses in all living things is indispensable in the defense against illnesses. Bouillie Bordelaise is allowed to be used in the organic food chain.
The first treatment of the season should be early spring, a day without rain and wind, when the buds on fruit trees, vines and roses are ready to burst. Make sure that the complete tree, vine and rose are covered with the spray. The second treatment should be in autumn, just after the leaves have dropped. My rose grower in addition sprays when the new rose leaves are on the roses, but with the recommended dose halved. Do not use it during the summer, if there are illnesses, they have by then manifested themselves plus the fact that certain plants do not like to be sprayed at that time of the year.
It comes in powder form, traditionally it is blue in colour, but a colourless version is available. The powder is dissolved in water, measurements given on the box.