covering roots mature tree

[superchief]

Have a mature 25' Japanese maple on a hillside where I must cover most of the downhill roots with 16" of soil as part of a grading plan. I would definitely like to save the tree and do not want to just trust the uphill roots to do it.

In order to allow air and water to get to the existing roots my thought was to cover the entire area with a series of perforated pipes in parallel, then landscape fabric, then washed stone, then landscape fabric, then 4" of soil. The pipes could be open to air at one end.

One issue this does not solve is encouraging new root growth at the higher elevation - I could add root hormone but it seems unlikely to do much if the new soil is a foot higher than the existing roots.

Cost is not a major consideration in saving the tree.

Do you think this will work or do you have a better way to suggest?

 

[superchief]

anyone have advice on this?

 

[TheJollyLogger]

No, it won't work. Japanese Maples are finicky under the best of conditions.

 

[superchief]

For others searching this question in the future ... I consulted with a local arborist who said he has done this many times, it is what they do for trees planted in the city.

He recommends doing a series of wrapped horizontal perforated pipes and some vertical ones coming to the surface to bring air down, a layer of clean stone, geo fabric, and then structured soil ... make sure there is some drainage at the bottom so you don't have excessive water collecting unless the soils perc very well.

 

[buzz sawyer]

Maybe find out exactly what types of trees this has worked on. If none were Japanese Maples, go with what the Jolly Logger said.