Does anybody have short term and/or long term results of root pruning mature Moreton Bay Figs.

Background: 50- 75 year old established Moreton Bay Figs in fair to slightly stressed condition with roughly 40% foliage density. There is a thick root mass in the top 12" - 14" of soil.

Problem: There is a proposal to cut the roots of the subject Moreton Bay Fig in order to accomodate a new driveway. Root diameters at the proposed location range in diameter of 1" and less up to 6" or more. The proposed driveway would be approximately 12' - 13' from the trunk of the tree. The DBH of the subject tree is approximately 22.5".

Thank you.
Walter Warriner

Reply to post by Walter Warriner, on July 21, 2000 at 18:08:42:

'Thought you might like to see what they can do...

Reply to post by Mark Goodwin, on July 21, 2000 at 18:08:42:

Mark,

Sad but true we removed a Ficus m. that size last month. Took five days including the stump.

As to sun sets. The look better in CA because you have not been to Australia!!! Come on down.

Mark

Reply to post by Walter Warriner, on July 21, 2000 at 18:08:42:

Walter,

Using Matheny & Clarks tree protection zone formula as a guide, a minimum of a 16'radius is suggested.
The premises are - average to excellent vigour, a good tolerance to root disturbance and a mature rating for the tree.
The shortcomings are - is the tree of average to excellent vigour? The species is certainly tolerant of root disturbance
as they are regularly and successfully moved in Queensland, Australia, often bare rooted. The tree is certainly mature.
Your post did not indicate whether the driveway was around or just past the tree.
Conclusion - I am assuming it's summer where you are which would put additional pressure on the tree especially if the
excavation is circular or semi circular. If the tree looses additional foliage as a result of the excavation, the
bark on the branches close to the trunk could be sun burnt, setting up the tree for additional repair work.
My thoughts would be to consider the minimum possible depth of excavation, with the maximum possible distance from the trunk,
closer to 20' than the 13', and that the job be deferred till fall. Care should be taken to sever the roots cleanly and
a suitable irrigation system should be installed well prior to the excavation, along with 4" of mulch under the entire canopy.
Would be interested to hear the results.

Regards

Leigh Stone