This year I'm changed my mentality from trying to fight back tree
roots in my garden to using them as a soil amendment.
For the last 4 years its been a losing battle, they grow right back in a thick mat after I've redug my beds.
I'd redig the beds partly just to cut the roots.
Now though I changing everything to
hugelkultur and thus a no-till approach so instead of cutting the roots right in the bed I
am digging a trench between the
trees and bed to cut the roots.
Thus the roots will be untouched in the beds but dead and decompose.
The trenches are refilled and I'll put a
drip line in to lead the roots back to the garden. Thus next year I'll know where the roots are to cut.
Hopefully this will work and every year a large mat of roots will be added to the soil as an amendment.
http://lowcostvegetablegarden.blogspot.com/2012/09/tree-roots-in-garden.html