Salutations Mirai Family,
I have this Juniperious Chininsus ‘Perfecta’…
Rob
This looks like a Gall of some sort. Which is often caused by an interaction between an insect and a fungus. Sometimes the insect introduces the fungus to the tree, often from laying their eggs in the tree and introducing a fungus in the process. There a lot of different types of galls for every species of tree and it gets pretty complex when you study the vectors that cause them. But basically there is some fungus or bacteria or virus probably in your tree that is causing the plant tissue to mutate into this “tree tumor” of sorts. It most likely will not harm your tree’s overall health but it will probably continue to grow in size (like a tumor does) and be very unslightly. My recommendation is to cut it off. If only for aesthetic reasons.
The juniper looks to be reacting to damage of some form by increasing vascular tissue in that area. @Mike_Hennigan is probably right with the gall.
I managed to damage a juniper branch when first trying to wire. I thought I had killed the branch, but it fought back and created what looks like a goiter.
