In this guide, you will find out how to remove these Mushroom Plant Vines God of War Ragnarok. You have to be on the main story quest of the Path and come here with Freya.
So when you complete this Mission, she will explain how you do it using the ability. You have to hold L2, aim at it and press square. She will fire her ability and then you have to use your chain. So you have to switch to the chains, and then hold L2 to aim and then R2 to set on fire.