On 14 May 2004 13:54:31 -0800, (Roy A.
Fletcher) wrote:

My next-door neighbour has a walnut tree planted right on the
property line. My failure to grow potatoes and tomatoes has
been attributed to a substance called juglone that emits from
the roots of walnut trees.
So this summer I'll try alternate crops. I've been assured
that carrots are okay, but can find nothing on beets, yams,
sweet potatoes, cabbage or any of various turnips. Various
squash thrive on the soil.
Would like to determine any method that will enable tomatoes
to grow.

Containers. Seriously, I've not heard of any method of counteracting
or neutralizing juglone, and tomatoes and potatoes are most often
mentioned as affected plants. I didn't believe in juglone because many
people simply speak of it as being "poisonous to plants," which can't
possibly be true, because my back yard had 5-6 giant old black walnuts
and also plenty of grass, bulbs, flowers, and weeds. Then I learned
the intolerance was plant-specific. As specific information (except
about tomatoes and potatoes) seems to be scarce, I imagine you'll just
have to try other food-plants and see what happens. I've never tried
to grow veg in my yard because the walnuts also provided plentiful
shade. All but one tree were destroyed by Isabel last year, so I may
be able to experiment now. Oh, I *did* have successful asparagus in
one sunny patch.