Is it okay to use BLACK WALNUT LEAVES?
Black walnuts produce a substance called juglone, which is toxic to other plants and inhibits their growth. Juglone breaks down in hot compost, but since the entire pile might not get uniformly hot, there could possibly be juglone in the finished compost. Its controversial to use black walnut leaves, and there are various arguments out there So to be on the safe side, you can make a SEPARATE pile for them (see the eucalyptus question below), or send them to a large-scale municipal composting facility with higher temperatures than typically achieved in a backyard pile.
