In his early research projects, Dr. Whitcomb tested numerous container designs. Milk cartons (today “tree bands”) only prune roots at the bottom, creating few side branches. Containers with vertical slots still result in circling and excessive water loss. These and other designs were rejected until root-pruning containers evolved to the current line of patented RootMaker® products.
• 1968- Grew trees in bottomless milk cartons.
This design only prunes at the bottom.
• 1970- Tested slotted container. .
Very little root pruning, high water loss
• 1973- Pot-in-pot experiment.
Large circling, escaping roots.
• 1973- Root pruning via copper toxicity.
Long term toxicity issues.
• 1983- Evaluated a porous fabric container above ground.
Inconsistent root pruning, root escape.
• 1984- Patented root tip trapping container, no holes.
Inefficient pruning, still some circling.
• 1985- Patented first version of fabric in-ground container.