The Collaborative International Dictionary of English v.0.48:

Tub \Tub\, v. t. [imp. & p. p. Tubbed; p. pr. & vb. n.
   Tubbing.]
   To plant or set in a tub; as, to tub a plant.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Tubbing \Tub"bing\, n.
   1. The forming of a tub; also, collectively, materials for
      tubs.
      [1913 Webster]

   2. A lining of timber or metal around the shaft of a mine;
      especially, a series of cast-iron cylinders bolted
      together, used to enable those who sink a shaft to
      penetrate quicksand, water, etc., with safety.
      [1913 Webster]