4 Different Harmful Juniper Tree Diseases

The juniper tree is prone to some rust diseases, as well as diseases that are caused by different types of insects. Many of them are harmful to the plant, but they are not always deadly. However, if you let them go untreated, you do pose a very high risk of losing the tree. By knowing what you should look for, you will be able to find the correct way to treat any of the problems that you come across. Here are three different diseases and one of the major insects that infect the juniper.

Juniper Apple Rust

Juniper apple rust is a rust that transfers between the juniper and the apple tree. One season it will be on the juniper tree and then it will migrate to the apple tree to complete the cycle. The juniper apple rust tends to only last two years for its full cycle. The juniper tree should not have too much trouble healing itself from this rust unless the infection was massive. Even with a massive infection, you can sometimes save the tree with proper trimming and care.

Bag Worms

Although it is not a disease, it is worth mentioning that junipers attract bagworms. These little brown worms carry their feeding sacs around with them while they travel and feed off of the juniper tree. If they are left alone and allowed to multiply, the bag worm can kill the juniper. It is best to pick them off as you see them and in the spring treat with proper insecticides. The bagworms can go unnoticed until it is too late because of their shape and color. They are a reddish-orange color and are shaped almost like pine needles. It is important to get rid of them as soon as you see them so that they do not strip the tree of its foliage and kill it.


Blight is a form of fungus that grows on junipers. It will turn the tips of the branches black. The fungus will eventually destroy the whole branch and eventually can kill the whole tree if left uncontrolled. It is recommended that you remove the affected branches and burn them in order to try and stop the spread of the fungus to other areas of the plant.

Sooty Mold

Sooty mold is a fungus that is grown on the sugary honeydew that insects such as aphids excrete. If the insects live on the juniper, the mold is most likely present. It is best to control the insects in order to control the mold problem. No insects, no mold.

There are many different types of diseases and insects that can affect the juniper tree. If you are able to educate yourself on the different types of diseases, you will be able to identify what might be wrong with your juniper. Once that is figured out, treating it should be simple.