Top Reasons to Mulch Your Trees

Mulch is important to any tree’s health. But what exactly is mulch? Mulch is defined as any material placed around plants to improve the soil. Whether it is the layer of duff on the forest floor, or the wood chips from a recent landscaping project, mulch benefits trees in numerous ways.


Here are just a few reasons to place mulch around trees:


Insulation: A layer of mulch can insulate the soil, keeping it at a moderate temperature.


Moisture: Mulch can trap water and help to keep soils, and therefore tree roots, moist.


Weed Suppression: Mulch does a great job of keeping any unwanted volunteers away by blocking their access to sunlight and the sneaky weeds that get through are much easier to pull in a recently mulched bed.


Nutrients: Organic mulch decomposes into essential plant nutrients such as Carbon and Nitrogen. Mulch also prevents these nutrients from draining away when it rains


Humus: Organic mulch can decay into a rich material known as humus. Humus improves the soil by increasing porosity and reducing soil compaction.



These are just some of the reasons to use mulch. But with so many different types of mulch out there, what works best for trees?

As arborists, we always recommend wood chips. Wood chips are a great organic material that have all the above benefits, as well as as the added bonus of repurposing a tree


Follow these instructions when applying wood chips to your tree


  1. Use arborist wood chips. These are rarely uniform in size and contain a good mix of woody and leaf matter, decomposing and adding nutrients for both the short and long term with their variance in composition.
  2. Weed the area around the base of the tree first. These species are competing with the tree for nutrients and it is best for the trees health if they are removed before the mulch is applied.
  3. Apply 2-4 inches of mulch in a ring around the base of your tree. Be sure not to get the wood chips on the trunk as that can often invite decay and other problems.
  4. Make sure the ring is flat and uniform in thickness and avoid the “Mulch Volcano.” While it might be tempting to turn your mulch ring into the next Mt. Rainier, if the mulch is piled too high it might cause the tree to root into the mulch.

By following these steps, your newly planted tree will thrive, and be a benefit to you and your property for years to come.


For more mulching techniques, refer to this handout from the International Society of Arboriculture.


Looking for wood chips? Check out Chip Drop.



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