"art of laying out grounds and arranging plants and trees for picturesque effect," by 1861, verbal noun from landscape (v.). Earlier in the same sense was landscape-gardening (1763).
The question, however, is, Can landscape-gardening (or short and sweet, landscaping) be taught? It, plainly, cannot. ["The Gardener's Monthly" July 1861]Also, in reference to the visual arts, "depiction as a landscape" (1868).