Inspecting a Root System
Should a question arise in Mr. Burbank's mind as to why a particular plant is not thriving just as it ought, he may "go to the root of the matter" in a literal sense, to see if he can find out what is wrong. Of course such an examination must be made very carefully, and it is not to be recommended as regular treatment for many plants, but on occasion it may be of service to dig into the ground beside the plant, and find out how its roots are getting on. A young plant with defective roots is in precisely the position of a child with very bad teeth, it cannot possibly get proper nourishment.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 7 Chapter 1