In article ,
David Ross wrote:

The major difference between a native oak and a planted oak is that
the former has a taproot while the latter generally has had the
taproot cut while being moved from a seedling container into a
larger container. Western oaks growing naturally require that
their natural environment prevail: lean soil and dry summers. This
is not true for planted oaks whose taproots were removed while
still young.

It is not true for many of the European oaks even when the taproot
is NOT cut. There is no problem gardening under them, except for
the fact that they cut out the rain and light. Generally, however,
there is little point in growing much except (mediocre) lawn and
deep woodland plants (including cyclamen) under trees that cast a
heavy shadow.

I should be surprised if the same were not true of SOME American
oaks, because their natural habitat varies so widely. Which does
certainly not argue against your point with regard to the drought
adapted ones, and probably some of the others.


Regards,
Nick Maclaren.