espalier

säleikkö, ristikko A latticework used to shape or train the branches of a tree or shrub into a two-dimensional ornamental or useful design, as along a wall or fence.
1974, (w), Monsieur, Faber & Faber 1992, p. 223:

The garment stalls carried the traditional blue vine-dressers' outfits, sunhats, and the great willow pitchforks grown in espalier at villages like Sauve.