On 2019-02-09 5:49 p.m., U.S. Janet B. wrote:
> On Sat, 9 Feb 2019 17:30:43 -0500, Dave Smith

>
> I assume that you are keeping all the black walnut leaves picked up?
> That's about all you can do. I don't know if encroaching roots are
> able to 'poison' the soil. Good luck with that.

From what I have read, the toxic jugalone is mainly in the roots, buds
and nut hull and there is not much in the leaves or stems. The
squirrels gather up most of the nuts and take them to various locations
to be processed because I see piles of rotten old hulls around those
spots. The leaves get mulched by the mower. It doesn't seem to bother
the grass. On the contrary, some of my thickest and weed free stretches
of lawn are around the black walnut trees. Chives have been growing
wild around one of them for the 40 plus years I have lived here.
One of my spring projects is to move the black currants and blue
berries away from the black walnut trees.