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How to Treat Fire Blight with White Vinegar Spray

Fire blight is an infectious bacterium that if left untreated will destroy an entire tree. According to Colorado State University, fire blight affects members of the rose family, including apple and pear trees, and is characterized by dead and dying branches, black spots, blackened leaves and oozing cankers. Treating fire blight is accomplished with pruning and the application of a white vinegar solution to create an acidic environment that the bacteria will find inhospitable.

Examine the tree for any twigs or branches that are affected by the fire blight.

Cut the branches and twigs at least 8 to 12 inches below the affected area or canker with a pair of sharp pruning shears.

Prepare a mixture of one part white vinegar and one part water in a plastic spray bottle.

Spray the cut with a healthy coating of the mixture. This mixture will create an unfavorable environment that will help prevent the fire blight from spreading.

Continue to monitor the tree and each time a new canker or affected area emerges, treat it in the same manner.

Treat Fire Blight With White Vinegar Spray

The bacterium Erwinia amylovora causes fire blight on species of the rose family (Rosaceae). Dip the shears in the bleach solution after each cut so as not to spread the infection. Cut off all branches at least 12 inches below the last branch that is wilted and discolored. Pour in 6 cups of water and then 4 cups of white vinegar. Pump the handle on the top of the sprayer to pressurize the contents. Remove dead leaves and plant debris at the base of fruit trees. Fungal spores thrive in dead matter. Place organic mulch around the bottom of fruit trees to keep any fungal spores from splashing up on your tree in heavy rains or when watering them.


Sterilize any tools used to cut away the fire blight with rubbing alcohol. This measure will help prevent the spread of fire blight by infected instruments.

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