"kate" wrote in message ...

Thanks - Juglone was the culprit mentioned, but the first mention was
the roots, as well as the leaves and hulls.Is it safe to assume that the
roots wouldn't extend further than the drip line?

Kate

The roots can extend beyond the drip line, but unless it is a fairly dry site, it is not common for
Black Walnut roots to extend much beyond it.

Bob Weinberger