I have a book, Toxic Plants of Texas, which is mostly a book for livestock owners. It says that the toxic agent, Saponins, are concentrated in the rootstock and young leaves of Pokeweed. And points out that pigs uprooting the plants and consuming them are the most likely to be affected, although other species can be affected. Also mentions people eating the young tender leaves as greens, but water must be changed during cooking. And although serious symptoms can occur in animals, it goes on to say:
"Consumption of the leaves usually produces only a transient gastrointestinal disease in ruminants. Cattle often consume small amounts of mature leaves with no ill effects."
I have some Pokeweed plants just outside my main fenced yard, but still within an outer fence. Birds like the berries and I like the birds, so they remain.They're also a nectar plant used by hummingbirds and insects occasionally when in bloom. If during a rainier year, too many come up, I have to take some out and prune others with branches that are blocking my pathway, but my region is usually fairly dry and the so-called "soil" not very fertile, so otherwise no problems.
