I am building a low level deck around a tree that is almost 7 feet diameter. This is the framing right now:

enter image description here

Originally I wanted to build a bench around it but I ran out of time and decking boards; BUT now, since I have tons of extra 1" drained rocks / gravels I am thinking about filling it up like below photo (from someone else):

enter image description here

My questions:

  1. Would this be bad for the tree? Will the base be harmed and kill the tree?

  2. Is 1" rocks too small? I could put something (like lumber) to prevent them sliding down and out.



Based on some answers below, I am thinking about a way to solve stump rot and drainage issue. What if:

  1. I staple landscape fabric / metal mesh in the bottom.

  2. Then fill with >5" rocks instead of gravels

  3. Leave like 1-2" of gap between rocks and decking boards if the rocks sit below the boards.

The reason I am sorta wanting to do this is because we have kids running around on top and I am afraid they fall or get their legs stuck around the tree. It will be a year before I get time to build the bench around this tree (due to work).


  • A suggestion to other who find themselves in a similar situation. Put a metal grate around the tree. duckduckgo.com/…
    – Alaska Man
    Apr 13, 2021 at 17:10

3 Answers 3


Covering any root area around a tree with more than half an inch or so of soil or stone will cause the roots to die in that area for lack of oxygen.

I would not recommend doing what you plan as there is a good possibility of die back from branches that no longer receive enough oxygen and water from the roots.

As others have pointed out the tree will continue to grow and push on the deck supports. If you really have to do this use screws that can be removed and leave the central area open.

Mature trees like things just the way they are and do not take well to changes in grade or the amount of water they receive.

In regards to your update the least intrusive way to deal with the central well is to use 4" diameter drain pipe with sleeve. Lay this down to occupy the space around the well then cover with mesh or geotextile. Top with bark or small pea stone. Nonetheless I do not recommend this as you are taking your chances that you will kill the tree.

  • Thanks. I have updated my question but appropriate ideas to handle the problem. Let me know.
    – HP.
    Aug 12, 2016 at 4:48

The tree will continue to expand as it grows. If you completely fill that space, it may start to push the rocks against the deck.
More important, whatever you do make sure there's plenty of drainage. The trunk will be at risk of rot damage if you surround it with materials that hold water -- and remember that it only takes a couple years for dust & dirt to fill in the gaps in coarse gravel.
Personally, both for the tree's health and for aesthetics, I'd leave the area open.

  • 2
    It's remarkably easy to end up with a 7 foot diameter dead tree in your deck. Proceed with extreme caution.
    – Ecnerwal
    Aug 11, 2016 at 14:13
  • What if I put landscape fabric below, nailing to the joists. Then put big rocks like 5" ones. There will be plenty of drainage. Would that be still a problem?
    – HP.
    Aug 12, 2016 at 1:43

I've found that trees and other plants don't grow as well with rocks or gravel on their roots... but since this is a large tree I don't think it will shorten it's life span as much (as a young tree).

Building around trees is tricky, and certainly not permanent. As carl said, leave room.

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