Orchards may fall silent in winter, but this stillness is deceptive. Invisible fungal spores and bacteria lie in wait under the bark, in cracks and around dormant buds. In an orchard that receives no winter treatment, these pathogens awaken with the spring and threaten an entire year's work. This is where Bordeaux mixture, backed by centuries of experience, comes in.
Why Bordeaux mixture?
Made from a balanced blend of copper sulfate and lime, this solution differs from ordinary sprays. It does not wash off in the rain, is unaffected by the cold and forms a long-lasting protective layer on the tree. It is the tree's winter armor, especially against bacterial blight, scab, monilia (brown rot) and the early stages of canker.
Three key advantages of winter application
- Complete coverage: Once the leaves have fallen, the spray reaches even the most sheltered parts of the branches, providing complete protection.
- Maximum effect: Targeting disease spores weakened by the winter cold is like striking the enemy at its weakest moment.
- Safe higher rates: Because the trees are dormant, stronger and more effective rates can be applied without the risk of damaging young tissue.
Timing is everything
A single application may not be enough for successful protection. The ideal schedule is as follows:
- 1st application: In autumn, once all the leaves have fallen, at the onset of winter.
- 2nd application: In spring, just before bud break, as winter comes to an end.
Remember: Bordeaux mixture is not a fertilizer that directly increases yield, but an insurance policy that safeguards it. A tree that enters spring free of disease, with its wounds healed and its surfaces clean, is always one step ahead at fruit set.