I have recently cut the stalks of my sunflower plants to harvest the seeds. Should I cut them to the ground at the end of the season or just leave them be? They look a little bare, as they are just stalks with large wilted leaves on them. Also, there are large black bulbous growths that have emerged where the stems of the leaves meet the stalk. Is that normal? Any help would be greatly appreciated. Thanks!
Yes, go ahead and cut back the stems. If the roots can easily be removed now, I would do so.
Sometimes you need to wait to remove the old roots until the remainder of the garden area has gone dormant.