Return to the Trees Forum | Post a Follow-Up

 o
Magnolia roots growing up?

Posted by Transplanted07 6 (My Page) on
Mon, Feb 25, 13 at 15:59

I have a magnolia growing *directly* next a retaining wall. The magnolia is well-established, about 10" diameter. The wall is about 3-3.5' high.

I'd like to back that wall a couple of feet away from the tree.

From what I read, magnolias have fairly shallow root systems. If the roots on the "high" side of the tree are only 18-24" deep by soil depth, that places them 1-2' *above* "level," higher than the actual root flare. Will magnolia roots grow against gravity? Am I risking exposing some of the tree roots by moving that retaining wall away from the tree?


Follow-Up Postings:

 o
RE: Magnolia roots growing up?

i have read this 3 times.. and i just dont understand ... what you are trying to say ... [dont worry.. its probably me ..]

a ten inch diameter trunk.. will be supporting a tree.. what.. with a 20 foot canopy ...

conceptualize that its root mass .... is twice that ... in a root form.. not the form of the tree ...

what you will be doing.. is severing a line of its roots back where you will be putting the foundation of your wall .. [you do not say its a retaining block wall with little or no foundation] ....

so in my mind.. your question should be whether digging out a few more feet.. in a straight line cutting all the roots back there.. will have a major impact on a very large tree ...

and frankly.. we can all do our best chicken little act on how its no good.. but until you do it ... no one will really know .... its your call ...

so i am really wondering.. how you worked gravity into the equation ... lol ...

now .. all that said.. you 'SEEM to indicate that you are moving this wall for the sake of the tree ... and that makes no sense to me at all.. a tree that grows to that size is having no issues with that wall .. so why do you??? .. you may be trying to fix something that isnt broken ....

a picture would sure help us understand where you are going with this ...

good luck

ken

ps: a tree puts its roots where it is most advantageous for vigor.. and if it takes defying gravity ... i would bet my nickle.. they could find a way to do it.. lol ...


 o
RE: Magnolia roots growing up?

It's not a matter of the roots "defying gravity". It's a matter of them seeking specific soil conditions (oxygen, moisture, etc). If the roots were able to grow underneath the footing of the wall, they would surely head straight (well, maybe crooked) for the upper level of soil on the other side (high side) of the wall. Now the question is whether the roots have ventured under the wall, and by how much. That will depend on how the wall is built, the type of soil you have, and who knows what else. I don't know how to predict what has actually occurred without probing/digging in the area a little. If your current wall foundation is deep, you may not have many roots under the wall.


 o
RE: Magnolia roots growing up?

  • Posted by bboy USDA 8 Sunset 5 WA (My Page) on
    Tue, Feb 26, 13 at 16:07

Demolish the wall without seriously whacking the tree (including the roots), then make the new wall where wanted. Again, without cutting into or banging the tree. Fill in with soil as needed, in order to maintain the grade at the right level for the tree. Do not bury the base of the trunk with a fill, or cover a large portion of the root zone with a fill. Around and beneath trees the main thing is to avoid compaction, cuts and fills.


 o
RE: Magnolia roots growing up?

@ken_adrian, good questions. The wall is not moving for the sake of the tree. The wall is coming down because it's hideous and slapdash. It's going back up (with better construction and nicer materials) because it's necessary. Perhaps I should have included this detail from the start, but my thought is not so much to back up the entire wall, but to rebuild it in two levels, terraced if you will. The lower half of the wall will likely remain where it is, but I'd like to push back the top half of the wall, which should help open up the whole space.

@brandon7, Thanks. I hadn't given much thought to the foundation of the existing wall inhibiting root growth in that direction. I'll have to take a good look at what kind of effects it has had.

@bboy, Thanks for the response. The wall is mostly dry-stacked, so demolition shouldn't be too chaotic around the tree. Thanks for the warning about fills.

All, thanks for the advice. It sounds like my best approach will be to proceed carefully, adapt to whatever root situation I find, and put together something attractive and long-lasting, while minimizing impact to the tree and roots.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Trees Forum

Instructions

  • You must be a registered member and logged in to post messages on our forums.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review the contents and make changes.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • It is illegal to post copyrighted material without the owner's consent.
  • HTML codes are allowed in the message field only.
  • No advertising is allowed in any of the forums.
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.



 
Click here to learn more about in-text links on this page.