Black Walnuts and Hackberries are symbionts for one another, and
allelopathic for separate but overlapping groups of understory plants.
The late leafing out, and early dormancy however makes Bl. Walnut a
great candidate for guild building, if you know which species to use.
In Urbana, IL we grow the following under a 150 year old Juglans nigra
surrounded by hackberries and suburban development:
The recently published Gaia's Garden (Hemmingway, 2001) uses Black
Walnut as its primary example for a tree guild and includes Wolfberry
and Hackberry... we've also found that Dandelions, Violets, and
Creeping Charlie have outcompeted any grasses growing underneath the
Black Walnuts in Urbana, IL... given the absence of a mowing regime,
that is. It is also a fine environment for controlling a small patch of
Sunchokes (Heliantus tuberosa) and Lamb's Quarters (Chenopodium).
The point is that you can grow stuff underneath Black Walnut if you
experiment. Everything else we've tried is dead.
Rob
Urbana Permaculture Project
[permaculture] Black Walnut Guild,
urbana permaculture project, 12/02/2002