Source : Webster's Revised Unabridged Dictionary (1913)

Garden \Gar"den\, v. i. [imp. & p. p. {Gardened}; p. pr. & vb.
   n. {Gardening}.]
   To lay out or cultivate a garden; to labor in a garden; to
   practice horticulture.

Gardening \Gar"den*ing\, n.
   The art of occupation of laying out and cultivating gardens;
   horticulture.

Source : WordNet®

gardening
     n : the cultivation of plants [syn: {horticulture}]