Treers wrote:

Behind my new house (zone 6) there is a huge maple, probably 5-6 feet in
diameter, which the previous owners allowed to be swamped by english ivy.
I'm guessing that from time to time someone went over the patch with a
lawnmower but did nothing to actually uproot the ivy. I've pulled out the
mat about a foot from the trunk but I'm wondering how much more I should
yank it out -- it extends probably 4 feet from the trunk, so I'm guessing
it covers 100+ square feet.
Would it make more sense to just cut and yank out the ivy as it reappears
and let the roots starve to death, then let the mat slowly decompose, or is
more active removal wise? I know that ivy roots are very resistant to rot,
so I'm reluctant to let nature run its course if that means smothering the
roots of this tree.

The tree is 5-6 feet in diameter. The ivy is in a ring only 13-14 feet
in diameter (4 feet outside the tree trunk). The drip line is much
bigger than this. I doubt that the ivy is interfering with the roots
much any more. Probably just mowing it would keep the ivy in check and
keeping it away from the bark will keep the tree healthy.