Roots going around the trunk of a Red River Birch tree because of volcano mulch.

Asked October 1, 2016, 10:56 PM EDT

We had put too much mulch around our tree and when trying to lower the mulch saw that some of the root was going around the trunk. There are big roots that have grown as normal from the tree. My question is should we remove all the mulch down to 2 inch level without doing more damage with having the one root growing around the base of the tree.The tree is 17 years old and around 40 feet tall. Any information you can give us is greatly appreciated. Thank you, Linda Lehman

Summit County Ohio trees and shrubs

1 Response

Hi Linda, Yes, for sure remove the volcano mulching from the base of the tree. The response that you see from the tree is that it will grow lots of roots into the mulch and you have found that they often send out a root that will "girdle" the main part of the roots. As the girdling root grows it will strangle that part of the tree and sometimes it will send it into a decline and the tree will die. I would however wait a little as all the food that was created in the top of the tree all summer is now moving down to the roots and will be stored there for next season. Generally, nursery people know that and will delay digging trees until there is a major drop of leaves which means that the tree is now mostly dormant and the reserves for next year are stored in the root system.

When you do take the girdling root off, use sharp cutters and make a clean cut. That is the best way to treat this problem. I've watched "landscape crews" edge around trees and usually they take a divot of sod away from the edge of the bed. Then instead of throwing the divot into a wheelbarrow and hauling it away they just add it to the mulch pile around the tree. The result is that after a couple of years the mulch gets the added divots plus more mulch and it get higher and higher. It is for sure not good for the trunk at the ground level as it can cause rot and also kill the tree over time. The other practice that is seen is to make a small bed for some annuals around the base of the tree. After a few years the tree starts to yellow and go downhill. Flower beds need sun for the most part and can't compete for moisture to that extent.

Again, yes remove the mulch or make a larger ring of mulch around the tree with the excess mulch. Take the girdling root off but wait a week or more for the tree to go dormant.

Hope this helps, Don.