Flowering Shrub ‘Bloomerang’ Lilac
Disease Alert: Cedar Apple Rust
With all the rain we have had the last few days many people have come into us with samples of their junipers with a substance on the branches that looks like orange marmalade. Don’t worry, there isn’t a nut going around spreading jam on your bushes. It is a fungus disease called cedar apple rust.
Cedar apple rust got its name is because it only attacks apple trees and certain types of junipers, the most common being the eastern red cedar. It can only attack these two plants when they are in the vicinity of each other so if you have this on your junipers it means either you have a crabapple tree or apple tree in your yard or somebody in your neighborhood does.
The reason this just showed up overnight is because you probably didn’t realize that your juniper had small galls on the branches already from prior infection given to it by the apple tree. When they got soaked in the rain, they expanded to form those orange growths. It won’t do much damage to your junipers other then make them look very ugly. Control is easy. Spray your junipers and any apples in your yard with Bonide Copper Fungicide or Bonide Infuse Systemic Fungicide. Because these two plants give each other the disease, if you can stop the fungus cycle on one of them, it will prevent the other from getting it.
As always when your junipers or any plant in your yard gets a disease, please bring us in a sample for positive identification and we can help you with a remedy. You should also feed any of your shrubs with an insect or disease problem with Espoma Bio-Tone and Espoma Holly Tone. This will help strengthen them and get them back to health.