Silver Maple and Rock Mulch

Question: Hello! I have a silver maple at the front of my house (south-east sun exposure). Shallow tree roots are starting to be exposed. I've read that mowing the lawn can nick and damage the roots. I was thinking of tearing up the turf and adding ~2 inches of rock mulch. Is this a good idea? I don't want to use an organic mulch because we are in an area of high-winds and on the outskirts of the urban wildland interface. But will the rock mulch hold heat and possibly damage the shallow root system? Thank you!

responder: Jefferson County Extension of Colorado State University  Replied May 17, 2023, 2:14 PM EDT
response: Hello there and thank you for using Ask Extension.   Thank you for the photos.  It appears that your roots are seeking air.  This is pretty normal for our clay soils, which do not have a lot of air space.  Based on this assumption, I would not recommend you cover up the roots with anything.  They will either grow up further, or suffer from a lack of air/oxygen.  Unfortunately, there is no cure for this issue.  You'll just need to be careful when mowing around the roots because as you know, if the roots become injured, your tree could have severe problems.  Here is a fact sheet call "Healthy Roots and Healthy Trees."  Be sure to check out the section on "Causes of Root Injury and Disease."  It specifically discusses the harm in adding soil on top of the roots.   https://extension.colostate.edu/topic-areas/yard-garden/healthy-roots-and-healthy-trees-2-926/  You could create a ring around the area to protect the roots while mowing,  but I would not recommend rock.  Here is a fact sheet about mulches.  There are good descriptions of mulches you may not have considered. If you choose to add something like pine needles or gravel, don't cover up the roots.  The primary purpose of this ring is to protect the roots.  https://extension.colostate.edu/topic-areas/yard-garden/mulches-for-home-grounds-7-214/  I hope this answers your questions.  Good luck.     Jeff C, clinician

responder: The Question Asker Replied May 30, 2023, 11:13 PM EDT
response: This was a very comprehensive response, thank you!!!Between the wind and the heat risk, it doesn’t seem that any of the mulches recommended would be a good option. If I’ve missed something, please let me know!Thanks again,AlyssaOn Wednesday, May 17, 2023, Ask Extension <<personal data hidden>> wrote:-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-Dear Alyssa, here's the response to your question: Hello there and thank you for using Ask Extension.   Thank you for the photos.  It appears that your roots are seeking air.  This is pretty normal for our clay soils, which do not have a lot of air space.  Based on this assumption, I would not recommend you cover up the roots with anything.  They will either grow up further, or suffer from a lack of air/oxygen.  Unfortunately, there is no cure for this issue.  You'll just need to be careful when mowing around the roots because as you know, if the roots become injured, your tree could have severe problems.  Here is a fact sheet call "Healthy Roots and Healthy Trees."  Be sure to check out the section on "Causes of Root Injury and Disease."  It specifically discusses the harm in adding soil on top of the roots.   https://extension.colostate.edu/topic-areas/yard-garden/healthy-roots-and-healthy-trees-2-926/  You could create a ring around the area to protect the roots while mowing,  but I would not recommend rock.  Here is a fact sheet about mulches.  There are good descriptions of mulches you may not have considered. If you choose to add something like pine needles or gravel, don't cover up the roots.  The primary purpose of this ring is to protect the roots.  https://extension.colostate.edu/topic-areas/yard-garden/mulches-for-home-grounds-7-214/  I hope this answers your questions.  Good luck.     Jeff C, clinician  Need to reply to the expert? Click the link below, or simply reply to this email. Click here to view #0099755 Jefferson County Extension of Colorado State University Plant Diagnostic Clinic <personal data hidden> <personal data hidden> https://jeffco.extension.colostate.edu/horticulture/clinic/ Call or email for hours and sample submission guidelines We hope this response has sufficiently answered your questions. If not, please do not send another email. Instead, reply to this email or login to your account for a complete archive of all your support requests and responses.

responder: Hania Oleszak  Replied June 06, 2023, 3:29 PM EDT
response: Hi Alyssa, Bark chips and wood chips generally don't blow away easily, so that could be a good option to try for a mulch in your situation. Hania