How do roots of the magnolia rate on the sensitivty to disturbance scale? I'm a planner for local government charged with tree preservation enforcement( a first for our area!) on a proposed development site. I have required the use of a local arborist, and from the developers' reaction I might as well have specified a witch doctor. Political pressure is mounting for the plans to be approved with an arborist to be consulted after the land disturbance permit is issued (goodbye trees). If disturbance must occur, what measures should be employed to minimze stress. Will plywood sheets protect roots from compaction/damage from construction vehicles? This construction site in richmond, VA is home to a group of 6"-8" caliper magnolia that were planted about 8-10 years ago. Proposed onstruction activity includes grading cut and fill adjacent to the trees (within 5 feet of trunk in some cases. Also, the installation of an underground sewer line (5 feet deep) is proposed run between two of the trees which are spaced 12 feet apart. Boring for the line is proposed for a distance of 12 feet (6 feet on either side of the trunk). Is it better to bore directly under one tree rather than between two? Any input would be appreciated, especially timely advice.

Reply to post by Jeff Lamson, on February 10, 2000 at 12:34:03:

A tough situation when starting out, Jeff. I work under contract for several municipalities with similar ordinances.

First, I suggest you stand your ground with the developers, despite the pressure. The problems don't go away when the developer does- they last long afterwards, and someone else has to pay for the declining and dying trees. Good tree protection can add significant value. Encourage them to do a good job, and to use that in their marketing efforts.

The magnolias should do OK if they are only 8 to 10 years and 6 to 8 inches. I would consider 5 feet of clearance an absolute minimum (not having seen the trees or the site, of course). Our usual recommendation is protective fencing, either semi-temporary chain link, or at least the orange construction fencing. Be sure to specify steel posts, attached securely at least three places on each post, and not more than 8 feet apart. Fencing is to be shown on site plans and installed accordingly before approval of grading permits.

Compaction- plywood will not last long under heavy equipment making several trips. It will soon splinter, and soft soil will still compact easily. The best option (for the trees) is to keep the equipment away. No equipment encroachment, no cut or fill soil, no stockpiling of soil or construction materials or debris in the protected zones. Check the basic list of tree protections in the Tech Reports section of this site (link at top and bottom of this page).

Trenching- tunnelling is much better than trenching. For those magnolias, staying at least 6 feet away should be OK, for the access pits. Staying between the trees will keep the root damage to a minimum. The deeper the boring, the less likely you are to hit major roots. Be sure to keep all equipment from encroaching on the area near the trees, at the surface.

Good luck with the project. Hope this has been of help.

Reply to post by Russ Carlson, on February 10, 2000 at 12:34:03:

Thanks for your reply.