Black Walnut thuggery

by Liz Handler
(Syracuse, NY)

Hi,
We have two old, beautiful black walnuts at the back of our yard. Our compost heap is somewhat close to them-about 15 feet. If I use the compost on or near my tomatoes, will they be adversely affected by the black walnuts' "juju"?
Thanks,
Liz

Doug says that the black walnut secretes a chemical called juglone into the soil from its roots. This is what slows down and kills a range of plants.

Are there Black Walnut roots in your compost? If so, there's some chemical there. If not - no problem.

How much / how many roots are a problem? This sounds like a really variable question - a maybe-yes, maybe-no kind of thing and I wouldn't even hazard a guess.

So - as long as there are no serious root infestations, I'd go ahead and use it. If there are serious infestations of roots, then I'd be rebuilding the compost bin/pile to prevent them from gaining access. Or move the compost making to some other area where the Black Walnut roots aren't going to be a problem.