The mixture works with any type of fungus, prevents the formation of rot and rust, restores immunity and stimulates plant growth. Issues such as downy and powdery mildew, and black spot can all be controlled with proper application. Bordeaux mixture for roses is an effective remedy for controlling microscopic pests. Bordeaux mixture is applied when plants do not have their leaves. · heres the best method to apply bordeaux mixture to fruit trees or ornamental trees, whether youre tackling fungal diseases or using it as a preventative spray. Indeed, moisture and warmth are the two conditions that trigger fungus growth. It is often used in spring when diseases develop. · apply bordeaux mixture during the dormant season: If you apply it in spring or summer, it may damage the plants foliage. Spraying at this moment helps avoid that any given disease overwinters in the garden. · if you have trouble with fungal or bacterial diseases in your garden, bordeaux mixture may be able to help. · fall and winter are the best times to protect plants from spring fungal problems with homemade bordeaux mixture. For example, if you grow roses , you may have problems with diseases such as anthracnose, rust, leaf spot, or powdery mildew. Bordeaux mixture is also used in fall after leaves have fallen off trees. Because bordeaux can leave a blue-green discoloration on plants or painted surfaces, use it on dormant, deciduous plants that are away from buildings and fences.