Do sunflowers poison the soil?

Online Answer
He said wild sunflowers were ''notorious'' for being the most toxic, but all sunflowers give off at least some allelopathic compounds. They are present in all parts of the plant. Rain will wash some toxins from the plants onto whatever is near, and the compounds also leach into the soil from the roots.Jul 3, 1997.
Related Questions 📌
Once your sunflowers have died back completely and the backs of the blooms are brown, it's time to harvest. You'll also notice the seeds are plump and somewhat loose. Cut the stalk with sharp scissors or pruners, about one foot down from the flower head, and place in a container that can catch any loose seeds.
He said wild sunflowers were ''notorious'' for being the most toxic, but all sunflowers give off at least some allelopathic compounds. They are present in all parts of the plant. Rain will wash some toxins from the plants onto whatever is near, and the compounds also leach into the soil from the roots.Jul 3, 1997.
In other words, the corn roots can go after and utilize nutrients and water deeper in the soil profile than with any other crop. Sunflower, after corn, takes advantage of these root channels and follows them to extend further into the soil to find even more nutrients and water.