Cut “dead” roots?

[SouthPark]

Originally Posted by neophyte

maybe we can go the kindergarten route and place the stringy part in colored/dyed water and see whether the dye travels up the root.

Absolutely! And - for the science people in testing labs, they can help us to put trace elements into the reservoir. And if any of those trace elements get picked up in leaf samples etc, then they would be able to have this sorted very nicely.