I do not see knots in the roots so I would not think nematodes. I would do what Larry did except use hydrogen peroxide instead of bleach. But I think both work. I also would water the soil/ potting mix first with a stronger hydrogen peroxide mix. That kills anything in the soil. Wait a couple of hours for everything to dry. Sprinkle everything with cinnamon, roots and hole in pot. Where I dug them up from 1/2 to full strength hydrogen peroxide in the hole. A week later sprinkle baking soda lightly around and skip one year of planting there.
Many blessings for your success!
