If I want to plant a flower bed under my trees, how much of a soil/manure mix can I safely put around the tree without damaging the roots or compacting the soil?

Reply to post by David, on July 27, 2001 at 23:08:33:

Unfortunately, there is no correct or easy answer to this. The amount of soil you can put over the roots will depend on the soil type already present, the species, age and size of tree, how large an area you area working with, and a few other conditions. Generally, speaking, the less soil you add over the roots the better. Most healthy trees will tolerate 2 to 3 inches of loose soil, if the present soil is loose and not compacted.

If the trees are valuable, it's better to err on the side of caution. You might contact a local arborist to get some on-site advice. The International Society of Arboriculture maintains a current list of ISA Certified Arborists. The searchable list can be accessed at the ISA Web site, at:
http://www.isa-arbor.com

HTH

Reply to post by Russ Carlson, on July 27, 2001 at 23:08:33:

And it is best to use perennials then annuals, since regular tilling will break fine roots and stress the trees.

A "fire and forget" type thing like hasta.

Lastly check for incompatbilities like any nightshade member under walnut family trees. There is also some of theis (aelilopthy ) in norwy maple and some birch.