Tree Health After Paving

(Question)

Hi – I recently renovated my backyard and now I have stone pavers/mulch surrounding my 2 trees. It wasn’t until I finished it that I read about ‘mulch volcanoes’ and keeping the root flare exposed.

I tried to dig as much mulch away to expose the root flares of my 2 trees, but I’m afraid the pavers covering the root system may mean an inevitable death for my trees?

Is there anything I can do at this point?

(Answer)

As you have identified, keeping mulch away from tree trunks is an important practice to avoid retention of moisture against the wood and potential rot. Instead of the volcano method, where mulch is piled high against the trunk of a tree, mulching in a donut shape is encouraged to keep mulch away from the trunk. If space allows, you are aiming for 3 inches from the trunk, in a circle 3 feet wide.

Mulching aside, you do have reason for concern with the recent paving, likely soil compaction being a major issue. That being said, symptoms of construction damage may take years to appear and can be difficult to predict. Factors to consider include not only the extent of the damage but also the type of tree and the tree’s health at the start of the construction project.

Start by identifying the types of trees you have to get a better understanding of their tolerance for paving. The University of Minnesota Extension offers the following excellent resource: Protecting trees from construction damage: a homeowner’s guide.

You may also wish to speak with a certified professional arborist regarding your concerns. Visit the Ontario branch of the International Society of Arboriculture for more information.