Seed Saving: Dill Dill will cross pollinate, so isolate by 1/4 mile or only grow one variety. Dill tends to go to seed very early, so pull and discard the early bolters. Pick seed when dry. You can put a paper bag over the seed heads and tie it on to prevent seed loss. Put in a paper bag (label) and put in a glass jar and keep in a cool, dark, dry place tenzicut