**Read and follow all labels associated with the product you are using.** Most of the time, when a homeowner can apply a fungicide, it’s for a fruit tree or tree small enough to spray. Most options are very safe, but understanding what you’re treating will determine what type of fungicide you will want to use. The most general used fungicide for trees has a copper-sodium active ingredient. It’s a broad spectrum fungicide and does a good job of treating most fruit tree fungus and cankers. Spray trees from top to bottom in the spring. Most products will call for a second application within a month to a few weeks of the previous application. Read and follow all instructions on the label. If some is good, that doesn’t mean that a lot is better!
Link for broad spectrum fungicide
For treatment of bleeding canker and blue stain fungus, please use these two products combined. Read labels for mixing instructions and application rates and trimming.