Question
I read an earlier question about a shamel ash and am in teh same situation with mine, but hate to destroy the tree. The tree is 25-30 feet tall with at least a 10 inch trunk. It is 8 feet west of the corner of my house, 6 feet from the west edge of my patio and 6-8 feet from my block fence. It is putting out some vigorous root towards my foundation and patio. If I cut the roots, will it kill the tree? Should I just bite the bullet and remove the tree? I just have a bad feeling about the damage this tree could cause in the future since I read they can get to 80 feet and the roots get twice what the spread will be. It's growing very well, but is just in the wrong place. We never thought this tree would get so huge.

Answer
The Shamel Ash becomes a very large tree, up to 80 feet tall (24 m) in 30 years and almost as wide, usually around 45-50 feet tall and wide. It is shallow rooted, and its surface roots may be disruptive.


The shamel ash roots will  give you a problem with the side walks. Their roots are fast growing and aggressive and will extend put twice the width of the tree foliage. It more than likely will over time cause problems with the patio. The wall should be ok since the weight of the wall should off set the upward motion of any roots near the surface.  You can install a root barrier along the side near the patio or the wall. This would mean digging a trench along the patio and /or the wall putting a barrier in the trench to divert the roots. The over hanging limbs can also be a problem and will need to be watched and pruned as needed.


The roots and the foundation should not be as great a concern as the branches. If the branches grow to rub against the house, it will damage the tree and perhaps the house. The tree should be kept at least 20 feet from the house, this should be sufficient to avoid problems. This is farther than the branches will spread because this tree has a very upright growth form. The roots will extend much farther from the trunk than the branches; however, if your home has no leaks under the foundation, the roots will not grow in the dry soil under the house. The worst that would happen is that the roots will grow up to the foundation and then run parallel to the foundation.
Realizing the tree over time will get large as it grows and the limbs extend to the house the branches that touch the house will need to be pruned. This will be a future concern not one now.

You can cut up to 1/3 of the roots and not significantly damage the trees health. To calculate the % Draw a circle around the tree out where the branches extend and then draw a line through the circle where the roots will be cut. IF this cut off part of the "pie" does not exceed 30% of the roots surface (the full circle) then you should not have major damage to the trees health.


Here is web link to one of these type. http://www.biobarrier.com/biobinfo.html

This material is a thin plastic fabric containing small dots of hard plastic. These plastic dots are impregnated with an herbicide which will not kill the tree but will stop growth of roots as they approach the barrier. This chemical is usually trifluralin herbicide. This herbicide is not absorbed into the plant and translocated; therefore, it does not kill the rest of the plant. It has only low solubility in water and doesn't wash away to other places. This means it will stay in the region of the root barrier and not interfere with the growth of roots elsewhere. This method of root control will involve the least effort (trench one time) and should give many years of protection.

There are other type barriers that can be installed to block the roots. Check with your local nursery for these products.

Here is a link to these barriers.

http://www.4specs.com/s/32/32-9452.html

The answer as to where to remove the tree or use the root barriers will have to be yours based on the root system and the spread of the tree. Yes this tree can be quite large.