Resistant plants include black raspberries, corn, beans, carrots and zinnias. As any Kansan might expect, they also include dandelions. Even removing a juglone-producing tree won't have an immediate effect. Juglone-producing trees form the chemical in their leaves, fruit hulls, inner bark and roots. The leaves and nuts aren't major culprits in causing walnut wilt.
Rain can leach out their toxin, but soil quickly makes juglone inactive.
Roots, on the other hand, release the chemical directly. So any plant growing in direct contact with those roots may get a lethal juglone dose. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and research centers statewide. Its headquarters is on the K-State campus in Manhattan.