Tree Care Basics: Properly Mulch a Tree

Should I put mulch around my trees?

Yes! Chipped woody material, sometimes called "arborist chips," give the soil and your trees added nutrients, help retain much needed moisture, regulate soil temperature and reduce weeds. Combined, these can even help your tree grow faster.

How do I properly mulch a tree?

To properly mulch a tree, pread the mulch evenly around the tree, in a donut shape. Leave 3-6 inches around the trunk and avoid mounding the mulch against the trunk like a volcano. As a general rule, you should be able to see the root flare - this is the spot where the tree trunk and and the roots begin. Rake the mulch out in all directions to a distance of 3-6 feet from the center of the tree and 2-4 inches deep. This mulch ring will help retain moisture, cools the soil and reduces competition from grass. Over time, the mulch will decompose, adding essential nutrients back into the soil. Plan to replenish the mulch yearly to help keep your trees happy.

For quick reference, download Proper Mulching Techniques from the ISA (International society of Arboriculture).

Where can I learn more about the science?

The Elisabeth C Miller Library and University of Washington Botanic Gardens Gardening Answers database provides more details.

Now, how do I get chips?

Chips may be available from your project with Tree133. Please contact our office for more information. We also suggest signing up for ChipDrop - a free delivery service.

What if I'm still not sure what to do?

Please contact Tree133 if you have specific questions about how to use mulch to improve your trees' health.

updated 3/10/2022