Question
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Followup To HELLO! I MADE A MISTAKE. I HAVE A BLACK MAPLE NOT A OAK AND I LIVE IN A SUBURB OF CHICAGO. IS YOUR PREVIOS REPLY THE SAME FOR A MAPLE? HELLO! I HAVE A HUGE( 12 FEET AROUND) OAK TREE IN MY BACK YARD THAT I HAVE BEEN PUTTING RED WOOD CHIP AROUND FOR SEVERAL YEARS. THIS SPRING I NOTICED ROOTS COMING OUT THREW THE CHIPS. A COUPLE OF FRIENDS HAVE TOLD ME THAT IT IS NOT HEALTHY FOR THE TREE TO HAVE THE WOOD CHIPS AROUND THE TREE.SHOULD I REMOVE THE CHIPS? HOW DO I WORK AROUND THE ROOTS COMING UP? SHOULD I CUT THE ROOTS OFF?   
Answer -

Depends on the type of oak...a Swamp Oak, that lives its life submerged in the southern woods of the Mississippi delta or the Florida everglades actually grows "knees" up through the brackish water, like a snorkel.

IF you live specially California/Oregon -- STOP!! You WILL kill this beautiful native oak that grew happily in a field with limited water, for a century or more.  Also pull back the ornamentals that use lots of water outside of the drip line.  A big tree that needs removal is a sad thing...even sadder when it falls though your home.

IF you live anywhere else, generally, your friends are right.  Stop over-mulching the tree.  Total removal is not necessary, unless you don't like the look.  I'd lightly rake off this year's application, and TOTALLY remove any at the base of the tree, where the root meets the trunk.  It seems the old tree is adapting, but the trunk can get ringed by mold & diseases (like the dreaded Sudden Oak Death - SOD) that has the potential to "girdle" the tree and kill it.  

Even though it's a HUGE tree, it still lives in the top few feet of soil. The myth of a deep taproot for these majestic trees lives on.  It's not a carrot. Pruning a few of the roots won't hurt it, but slicing a trench along the trunk of it can.  

Here is a website (for California Live Oaks, etc.) that spell out the dangers of over-loving a tree.  

http://www.sierra2.org/viewpoint_articles/2005/dec2005/trees.htm

Generally, the slower growing a tree, the less adaptable it is to change.  If your oak resides in the Midwest of East Coast, then it can endure a bit more punishment...wetter, colder climates make for tougher trees and people!!  

Hope it helps.  Marc


Answer
Black Maples (Acer nigrum) are a shallow-rooted tree - their roots grow out for long distances (100 feet or more on bigger trees), and develop primarily within three feet of the soil surface.  They have many fibrous roots that can form a very dense root matrix, causing blocked drainage lines, or lifting of pavement.

Good news is that it's a "tough cookie" & native to the Northeast, and resilient to change - even though they grow slower than their other Maple cousins.

The bad news is the roots have probably already entered into the previous years' wood chips, so just lightly rake off some, and if you hit roots, stop.

I'd also still remove a circle of wood chips around the collar of the trunk, to prevent rot.  Also with maples, vermine like to eat the bark (hey, its sweet sap!), and could girdle the base, eventually killing the tree.   

Fore specific help in your area (Cook Co./Greater Chicago), check this site out:

http://web.extension.uiuc.edu/cook/urbanhort.html

Good luck!  -Marc